18 January 2008

January 2008

The farthest reaches of our solar system remain the most mysteriousareas around the sun. Solving the mysteries of the outer solar systemcould shed light on how the whole thing emerged - as well as how lifeon Earth was born.

Why the rainbow of colors in the Kuiper belt?

For instance, the Kuiper belt past Neptune is currently the suspected home of cometsthat only take a few decades or at most centuries to complete theirsolar orbits - so-called "short-period comets." Surprisingly, Kuiperbelt objects "show a wide range of colors - neutral or even slightlyblue all the way to very red," said University of Hawaii astrophysicistDavid Jewitt.

The color of an object helps reveal details about its surfacecomposition. It remains a mystery why Kuiper belt objects show a muchwider range of color - and thus surface composition - than otherplanetoids, such as the asteroids.

Some researchers had suggested volcanic activity could have led toall these colors - "absurd in the context of 100-kilometer-sized(60-mile) bodies," Jewitt said, as volcanism needs something bigger.

Jewitt and his colleagues had suggested that cosmic rays could havemade Kuiper belt objects redder, while impacts with rocks could havedug up more pristine matter that made them less red. Nowadays Jewittthinks there must be another explanation for this rainbow, but itremains unknown.

What is ultra-red matter?

There appears to be a material dubbed "ultra-red matter" that existsonly on about half of all Kuiper belt objects and their immediateprogeny, known as centaurs - icy planetoids orbiting between Jupiterand Neptune that very recently escaped from the Kuiper belt.

This ultra-red matter does not exist in the inner solar system, "noteven on the comets which come from the Kuiper belt. This suggests thatthe ultra-red matter is somehow unstable at the higher temperaturesclose to the sun," Jewitt explained.

The red colors suggest this substance might contain organicmolecules. Comets and other planetoids are often thought to have helpedbring organic molecules to Earth.

"In the Kuiper belt objects, organics might have been 'cooked' bycosmic ray radiation, giving them dark red surfaces, but there is noproof," Jewitt said. Ideally spacecraft could go out there and findout, he added.

Has the Kuiper belt shrunk?

Theoretical calculations suggest the Kuiper belt was once hundredsor maybe even thousands of times more populated than it is now. "Howwas 99 percent or 99.9 percent of the mass lost, and when?" Jewittasked.

One conjecture suggests when Saturn and Jupiter shifted their orbitsroughly 4 billion years ago, their gravitational pulls slung Kuiperbelt objects out of the solar system. Another says the Kuiper beltobjects pulverized themselves to dust, which then was swept away by thesun's radiation. Yet another possibility "is that we are missingsomething crucial and the conclusion that the belt is heavily depletedis wrong," Jewitt said. "All these possibilities are comparably hard toswallow, but would each be amazing, if true."

Secrets in the Oort cloud?

A distant reservoir of trillions of comets known as the Oort cloudtheoretically lies up to 100,000 astronomical units from the sun - anastronomical unit or AU being about 93 million miles (150 millionkilometers). This means the Oort cloud is a fifth of the way to thenearest star, so far away that objects within it have never been seendirectly, only inferred - but it must exist, given all the comets seenover the years.

The Oort cloud is the conjectured source of comets that requirecenturies or millennia to complete their long journeys around the sun.Since these "long-period comets" come from all directions, the Oortcloud is often thought to be spherical. However, while comets such asHalley's do not come from the Kuiper belt, their orbits also do notjibe with a spherical Oort cloud, Jewitt explained. This suggests theremay be an "inner Oort cloud" shaped kind of like a doughnut.

Astrophysicists think the Oort cloud is a remnant of theprotoplanetary disk that formed around the sun roughly 4.6 billionyears ago. Learning more about the Oort cloud could shed light on howour solar system - and Earth - were born, Jewitt said.

Are there more dwarf planets?

So far, three dwarf planets are recognized - Ceres, Pluto and Eris.The Kuiper belt, which lies about 50 AU from the sun, could hold some200 more. Beyond that there could be scores of dwarf-planet-sizedbodies beyond roughly 100 AU from the sun "that nobody had seen beforedue to their faintness and slow motion," said astronomer Chad Trujilloat Gemini Observatory in Hawaii. "Even a body as big as Mars could bemissed in our current surveys if it were moved beyond a couple hundredAU."�

Trujillo noted projects such as Pan-STARRS (Panoramic SurveyTelescope And Rapid Response System) and the LSST (Large SynopticSurvey Telescope) "should fill this gap in our knowledge in the comingdecade."

Where do the dwarf planets come from?

There are theories that the dwarf planets of the outer solar systemmay have dwelt in the inner solar system billions of years ago, basedon their current orbital trajectories. If so, "why are there so manyices on their surfaces?" Trujillo asked. Bodies in the inner solarsystem are generally expected to lose their ice due to sunlight.

Trujillo and his colleagues suspect the ice now seen on these dwarfplanets is relatively new, with such replacement ice coming perhapsfrom within these worlds, erupting out during "cryovolcanism." Ofcourse, further research is needed to see if such ice renewal would beenough to cover the dwarf planet after they voyaged from the inner tothe outer solar system, he added.

Do cosmic rays come from a bubble around the solar system?

When the supersonic wind of charged particles that flows from oursun collides with the thin gas found between the stars, the solar windessentially blows a bubble in this interstellar medium - a ball knownas the heliosphere.

Scientists have thought unusually weak cosmic rays - energeticparticles that zip from space at Earth - come from the heliosphere.Specifically, these rays are thought to come from the "terminationshock" - a shock wave of compressed, hot particles that results whenthe solar wind abruptly brakes against interstellar gas. (Thetermination shock appears to be about 75 to 85 AU from the sun.)

However, Voyager 1 saw no sign these anomalous cosmic rays wereproduced at the termination shock. "Perhaps it crossed the shock at thewrong time or place," said MIT astrophysicist John Richardson, orperhaps the standard view on how these anomalous cosmic rays aregenerated is wrong. Voyager 2 crossed the termination shock in 2007about 10 billion miles away from where Voyager 1 crossed it in 2004,and its data, which is still being analyzed, "may help us understandwhere these particle are produced," he explained.

The possibility of an asteroid walloping the planet Mars this monthis whetting the appetites of Earth-bound scientists, even as theyfurther refine the space rock's trajectory.

The space rock in question - Asteroid 2007 WD5 - is similarin size to the object that carved Meteor Crater into northern Arizonasome 50,000 years ago and is approaching Mars at about 30,000 miles perhour (48,280 kph).

Whether the asteroid will actually hit Mars or not is still uncertain.

Such an impact, researchers said, would prove an awesome blow forplanetary science since NASA's Mars Reconnaissance Orbiter (MRO) and aflotilla of other spacecraft are already in position to follow up anyimpact from orbit.

"An impact that we could witness/follow-up with MRO would be trulyspectacular, and could tell us much about the hidden subsurface thatcould help direct a search for life or life-related molecules," saidJohn Rummel, NASA's senior scientist for astrobiology at the agency'sWashington, D.C., headquarters.

Observations of the asteroid between Dec. 29 and Jan. 2 allowed astronomers to slightly lower the space rock's odds of striking Mars to about 3.6 percent(down from 3.9), giving the object a 1 in 28 chance of hitting theplanet, according to Tuesday report from NASA's Near Earth-Objectprogram office at the Jet Propulsion Laboratory in Pasadena, Calif.

But if WD5 does smack into Mars, some astronomers have a fair ideaof what havoc it may spawn. The likely strike zone would be near theequator, but to the north of the current position of NASA's Opportunityrover at Victoria Crater, NASA officials have said.

Mark Boslough, a collision dynamics expert at New Mexico's SandiaNational Laboratory, said the atmosphere at Mars' surface is similar tothat of Earth at an altitude of 12 miles (20 km). Some space rocks thattarget Earth explode under the pressure created as they stream into ouratmosphere. But they tend not to explode until much below the 12-milemark.

"So this won't be an airburst," Boslough said. "It will either hitthe ground intact and make a single crater, or break up and generate acluster of craters."

The collision, were it to occur, could also create a visible dustplume as ejecta is lofted high into the martian atmosphere, he said.

The resulting crater could reach more than a half-mile (0.8-km) indiameter, or about the size of the Opportunity rover's Victoria home,NASA added.

Boslough's break-up scenario is reminiscent of CometP/Shoemaker-Levy 9, which broke into more than 20 fragments as itneared Jupiter in 1994, then repeatedly pummeled the gas giant over thecourse of six days. The resulting impact scars were visible totelescopes on Earth, in orbit and NASA's Galileo probe, which wascircling Jupiter at the time of the collision.

Like Galileo at Jupiter, NASA's MRO probe and its High-ResolutionImaging Experiment (HiRISE) camera would be in prime position for amartian collision. With its ability to resolve objects three feet (onemeter) across, HiRISE as been billed as the most powerful camera eversent to study Mars.

"If the asteroid hits Mars, we'll get a great look at the craterwithin a few days of impact," said HiRISE principal investigator AlfredMcEwen of the University of Arizona's Lunar and Planetary Laboratory inTucson.

Gianyar, Bandung - Residents in Sukawati village in Gianyar regency,around 20 kilometers north of Denpasar, reported the appearance of amysterious crater in the middle of a paddy field Wednesday.

The hole was allegedly caused by a falling meteorite fragment.

One meter wide and around 30 centimeters deep, the cavity has turnedinto a large puddle in the heavy rains that have showered the areasince New Year's Eve.

Disregarding slippery paths leading to the site, hundreds of peoplecame to see the crater with their own eyes, and take photographs of itwith cameras and mobile phones.

"Residents heard an extremely loud gun-like explosion Tuesdayevening around 1 a.m. At the same time, a number of residents saw abright object falling from the sky," Made Tekek Arimbawa, aneighborhood leader, told reporters.

The hole first noticed Tuesday morning by I Wayan Miasa, 60, the owner of the field.

Made said he ordered the owner to wait for an explanation from the authorities before using the field again.

"We don't know for sure what it is," he said.

Sukawati police chief Comr. Ida Bagus Bedanajati said pieces of rock were found in the alleged meteorite crater.

"The rocks we found resembled pumice but didn't float -- it sank in water," he said.

He said the impact had not altered the structure of the soil or killed any plants or animals in the surrounding area.

"There were no casualties or material losses. What we do next is wait for the experts," he said.

The police had secured the area with a police line.

Bali is home to many mystic beliefs where odd and supernatural occurrences like flying fire balls are not unheard of.

The Balinese describe the occurrences as niskala which refers to the world of "unseen" phenomena.

Bandung Flight and Space Institute sun and space researcher ThomasDjamaludin said Wednesday he believed the unidentified object was ameteoric fragment.

He said he suspected a larger fragment had created the hole as itwas impossible for small fragments to create the loud noise heard byresidents.

The fragment would not cause radiation effects dangerous to humans, Djamaludin said.

Fragments were "only dangerous at the time of their explosiveimpact, with a fallout of hot debris ... After that they are harmless,"he said in Bandung.

Mammoth fossils around the Yukon are offeringevidence that ancient meteor explosions may have wiped out entirespecies there thousands of years ago, a California-based researchersays.

A team led by Richard Firestone, a nuclear scientist at the LawrenceBerkeley National Laboratory in Berkeley, Calif., made the discoverywhile testing thousands of samples of fossilized Alaskan mammoth ivoryfrom a suspected meteor impact that occurred about 13,000 years ago.

Firestone said he believes meteorites exploded over parts ofBeringia - the Ice Age-era region that includes parts of modern-dayAlaska, Yukon and Siberia - creating showers of fragments, or"micrometeorites," that struck and killed many of the prehistoriccreatures that roamed the area.

Furthermore, Firestone's team uncovered a surprise: The sample tusksdated back to about 35,000 years ago, meaning they were older than theblast from 13,000 years ago that they were initially studying.

"It turns out that there was an impact event, probably a meteor,that exploded over Alaska and probably over Siberia ... around thattime and embedded these particles into the tusks," he said.

"They probably came in under very high velocities, hundreds ofkilometres a second almost. It must have exploded and just embeddedthese things in the tusks in large quantities, as many as 100 or morein one tusk."

The small holes with meteorite fragments were found in about one outof every 1,000 pieces of mastodon ivory pieces Firestone's team hastested. They also found similar fragments in one Siberian bison skullthat appeared to have survived the blast, he said.

"In the bison skull, since that was bone, we could see renewedgrowth around these particles after they had been impacted. Sopresumably the bison - that particular individual, at least - survivedthe impact."

Now, Firestone is asking Yukoners for any mammoth fossil samplesthey may have. He is asking anyone who has found fossilized bone orivory with circular discolorations to try and collect soil samples inthe area where they found the fossil, then contact him at theCalifornia laboratory.

"We think they came from your area around the Yukon somewhere," hesaid. "So presumably [Yukoners] are going to be finding these things ifthey look for them."

Firestone's findings were presented last month at a meeting of the American Geophysical Union in San Francisco.

Washington: An asteroid that has a one in20 chance of striking Mars on January 30, might just fly past, whichwould probably make it target Earth at some point in future.

Designated 2007 WD5, the 160-foot wide asteroid was originallyidentified as a possible risk to Earth, though later analysis showedthat it actually might be on a collision course with Mars.

According to a report in Discovery News, Donald Yeomans, aplanetary scientist at NASA's Jet Propulsion Laboratory in Pasadena,California, has said that the odds are that the asteroid is going tofly right past Mars.

In the long run, that may not be good news for Earth, which couldfind itself in the asteroid's path at some point in the future."Something of this size could take out a fairly large metropolitanarea," said Yeomans.

But unlike the 1908 Tunguska event, when a large asteroid exploded over central Siberia with the force of a large nuclear bomb, now there would be advance warning of a possible strike, as well as the tools and knowledge to divert the threat.

Comment: Fromthe information available, it is evident that we are not prepared norhave the knowledge on how to divert such a thread. It was only thislast year that the mainstream media began even talking about thepossibility of a strike. Nope, no matter how reassuring the lastsentence of the article, it just ain't true folks!

The most intense meteor shower of the year hits Earth tonight. Ifthe skies are clear and you live at high northern latitudes, then youcould see dozens of Quadrantid meteors streaking over the pole.

Or you might spot a plane full of astronomers racing northward,trying to find out how this unusual meteor shower was created, andwhether it is the shrapnel of a celestial explosion witnessed in the15th century.

Like other meteor showers, the Quadrantids appear when Earth movesthrough an interplanetary stream of debris, which hits the upperatmosphere at more than 40 kilometres a second, vaporising to becomethe brilliant trails we see as shooting stars.

"It is our strongest annual shower, but one that is frustratinglydifficult to observe," says Peter Jenniskens of NASA's Ames ResearchCenter in Moffett Field, California, US. That's partly because of badweather in the northern hemisphere at this time of year. And unless youlive in the far north, the shower's radiant - the point in the sky fromwhich the meteors appear to radiate - is below the horizon.

This year Jenniskens will be joining other astronomers on a planefestooned with cameras, which will get above the clouds and fly fromAmes to the North Pole, keeping the Quadrantids in clear sight for 9hours. By tracking the arrival rate of meteors over that time, they arehoping to discover when this stream of meteoroids was born.

Dormant comet

Some meteoroid streams are created and maintained by active comets,which throw off bits of rock and soot as the Sun gradually evaporatestheir ices. But there is no active comet to supply fresh material tothe Quadrantids.

In fact, no parent body was known at all until 2003, when Jenniskensdiscovered that there is an asteroid following the same orbit as thestream. Jenniskens thinks that this object, 2003 EH1, is the remnant ofa dormantcomet that spawned the Quadrantids in a single violent event - perhapsan internal convulsion or an impact with another object.

Observers in China, Korea and Japan saw a comet in 1490 moving inroughly the same path as the Quadrantids. Could it have been a cloud ofdust surrounding the newly shattered 2003 EH1?

Mixed prospects

If the meteoroid stream was created so recently, it will have hadlittle time to disperse, and indeed observations suggest that thestream is narrow.

Jenniskens realised that Jupiter's gravity should deflect such anarrow stream, and he calculates that this year it would push thestream towards Earth. So if it really is narrow, we should hit it a fewhours earlier than if it is old, broad and undeflected.

If the shower was created in 1490, Jenniskens calculates it shouldpeak around 0200 GMT on Friday, making it ideal for European observers.If it is much older and more spread out, it should remain relativelyunaffected by Jupiter's gravity, and the peak should occur around 0700GMT - a good time for observers in North America.

For those of us stuck on the ground, viewing prospects are mixed.The rate of visible meteors could be as high as 120 per hour - if youhappen to be standing on a mountaintop in Norway. If you're in southernCalifornia, however, it drops to only 2 per hour. To see Jenniskens'predictions for your location, visit the "Fluxtimator".

Having recently written a review of New Light on the Black Death: The Cosmic Connectionby dendrochronologist Mike Baillie of Queen's University, Belfast,Ireland, I decided to go deeper into the subject. Over the past fewweeks a whole case of books I ordered have been arriving and gettingpiled on my desk after a quick thumb-through... so much to do, solittle time.

In the meantime, a friend of mine (who is a climate scientist at amajor U.S. research facility) turned me on to an interesting find, apaper addressed to the European Office of Aerospace Research anddevelopment, dated June 4, 1996, entitled: The Hazard to Civilizationfrom Fireballs and Comets by S.V.M. Clube. (For the uninitiated, Clubeis an astrophysicist at the University of Oxford).

In this short (4 pages) letter and summary statement, Clube writes (emphases in the original, make of them what you will):

Asteroids which pass close to the Earth have been fully recognized by mankind for only about 20 years. Previously, the idea that substantial unobserved objects might be close enough to be a potential hazard to the Earth was treated with as much derision as the unobserved aether.Scientists of course are in business to establish broad principles (egrelativity) and the Earth's supposedly uneventful, uniformitarianenvironment was already very much in place. The result was thatscientists who paid more than lip service to objects close enough toencounter the Earth did so in an atmosphere of barely disguisedcontempt. Even now, it is difficult for laymen to appreciate theenormity of the intellectual blow with which most of the BodyScientific has recently been struck and from which it is now seeking torecover.

I stopped right there and asked myself: Hmmm... just whatintellectual blow is he talking about here? After a bit of thought, itoccurred to me that he must be talking about the Comet Shoemaker-Levyfragment impacts on Jupiter which produced a huge amount of excitementat the time which was just two years before the date of this letter. Toreturn to Clube's report, he continues:

The present report, then, is concerned with those other celestialbodies recorded by mankind since the dawn of civilization which eithermiss or impinge upon the Earth and which have also been despised. Nowknown respectively as comets (>1 kilometre in size) and meteoroids(<10>

That he immediately switched from asteroids to comets seems toconfirm my speculation that he was talking about Shoemaker-Levy. But itgets more interesting:

Confronted on many occasions in the past by the prospect ofworld-end, national elites have often found themselves having tosuppress public panic - only to discover, too late, that the usualmeans of control commonly fail. Thus an institutionalized science isexpected to withhold knowledge of the threat; a self-regulated press isexpected to make light of any disaster; while an institutionalizedreligion is expected to oppose predestination and to secure suchgeneral belief in a fundamentally benevolent deity as can be mustered.[...]

(B) The present report based on the above grant addresses a varietyof issues within the broad context of the hazard to civilization due tofireballs and comets. It consists of:

(1) A brief statement of conclusions arising from a narrative report (3 copies);

(2) A narrative report (with appendix) linking the results of threescientific studies described in papers submitted to mainstream journals(3 copies)

(4) A co-authored foundation paper by Asher & Clube detailing the results from which items (3) and (2) progressed.

It is emphasized here that the present report expresses a viewpointwhich is contrary to the mainstream scientific theme currentlyreinforced through various US agencies in the wake of recent majorfindings under US leadership...

Despite the importance of this mainstream theme, it is recognizedhere that the cometary signatures in the terrestrial record aregenerally stronger than the asteroidal signatures in the case of bothlong term and short term effects i.e. those affecting biological andgeological evolution on the one hand and mankind and civilization onthe other..[...]

There are fundamental paradoxes to be assimilated as a result ofthis unexpected situation. Thus the perceived culture of enterprise andenlightenment which underpins the two centuries culminating with theSpace Age and which led mankind to spurn comets and fireballs may nowbe seen as the prelude to a profound paradigm shift: the restoration ofan environmental outlook more in keeping with that which precededAmerican Independence and which paid serious heed to comets andfireballs.

Clube then thanks the USAF for "its generous and timely injection offunds" and we note that the letter was cc'd to, among others, EdwardTeller at the Hoover Institute, S. Fred Singer at Fairfax VA, and JackA. Goldstone, Davis, CA.

I should add that, yes, I obtained the whole report and the papersit refers to (and more besides). The report makes one startling remarkthat I'm going to drop just to whet your appetite:

...the Christian, Islamic and Judaic cultures have all moved sincethe European Renaissance to adopt an unreasoning anti-apocalypticstance, apparently unaware of the burgeoning science of catastrophes.History, it now seems, is repeating itself: it has taken the Space Ageto revive the Platonist voice of reason but it emerges this time withina modern anti-fundamentalist, anti-apocalyptic tradition over whichgovernments may, as before, be unable to exercise control. ... Cynics(or modern sophists), in other words, would say that we do not need thecelestial threat to disguise Cold War intentions; rather we need theCold War to disguise celestial intentions! (emphasis in the original)

Just think about what this might mean, considering when it waswritten and all that has happened since. One might think the War onTerror was actually a planned cover-up...

Last week's Quadrantid meteor shower was probably debris from adeep-space explosion that went off in the late 15th century, newobservations reveal.

The meteors, which return every January, were observed more closelythan ever before when a group of 14 astronomers tracked them for ninehours on a flight from California, US, to the North Pole.

They found that the shower peaked at around 0200 GMT on Friday, matching a prediction made by Peter Jenniskens of NASA.

He based his prediction on the theory that the shower originated in1490, when observers in China, Japan and Korea saw a comet following apath similar to that of the Quadrantids. Apparently a sudden eventcaused the dormant comet to flare up - like Comet Holmes in October2007 - leaving behind a stream of debris.

Jenniskens calculated that such a young stream should be narrow, andthus easily deflected by Jupiter's gravity. That would make it arrive afew hours earlier than if it were an older, more diffuse stream.

Friday's observations confirm the story. A closer analysis of thenew data might also give astronomers some clues about what caused theoutburst.

The 1490 event left behind at least one larger remnant, a near-Earth asteroid called 2003 EH1.

Today we are going to look at the Summary of Conclusions about Fireballs and Meteoritesthat Victor Clube attached to his cover letter to the Chief, Physicsand BMD Coordinator of the European Office of Aerospace Research andDevelopment back in 1996, 5 years before September 11, 2001; that, anda few other things.

I often get accused of "fear mongering" because I keep bringing thissubject up again and again. I even think that it is fascinating thatthe big breakthrough in my experiment in Superluminal Communicationcame on the day that the fragments of Comet Shoemaker-Levy beganstriking Jupiter - even at the very moment of the first impact - andthat this communication with "myself in the future" has focused so muchattention on the subject of swarms of comets and comet fragments thatrepeatedly barrel through the solar system, wreaking havoc and bringingdeath and destruction to earth. As a result of the research prompted bythis communication, I wrote an entire 800 page book that is wovenaround the issue of cometary explosion type catastrophes that obviouslyhave occurred repeatedly throughout history: The Secret History of The World.

In the early days of publishing the results of this experiment, Iwas nonplussed by the many attacks I came under from all quarters. Iwas accused of "channeling aliens" (not true); of wanting to "start acult" (what is cultic about doing research into scientific subjects andexposing religion for the fraud it is?) and so on. That sort of thingreally hurt and puzzled me at first, but I have now seen it for theblessing it was: it has helped me to learn about the kinds of peoplewho are in charge of our world, the kind of people who want to keepsecrets so that they can hang onto power: the kind of people who createsuch things as "The War on Terror" to conceal from the masses ofhumanity the future that may very well bring our civilization to anend; the kind of people who know that survival of cometary bombardmentis possible and who want to be the only ones who do survive, and tohell with everyone else.

It is increasingly evident that intellectually the world is dividedinto two. There are those who study the past, in the fields of historyand archaeology, and see no evidence for any human populations everhaving been affected by impacts from space. In diametric opposition tothis stance there are those who study the objects that come close to,and sometimes collide with, this planet. Some serious members of thislatter group have no doubt whatsoever that there must have beennumerous devastating impacts in the last five millennia; the period ofhuman civilization. In a paper published in 2005, David Asher andcolleagues have looked at the objects that are known to have come closeto the earth in recent times. They conclude, based on various strandsof evidence (for example, the number of meteorites discovered on earththat originated on the moon) that the average time between impacts onearth is no more than 300 years, probably less. [Earth in the Cosmic Shooting Gallery]

Checking the authors Baillie is referring to, we find Bill Napierlisted. Napier is a colleague of Victor Clube. This brings us toanother division. There is a debate going on about this issue as wasmentioned by Clube in the first parts of the letter in question that Iquoted yesterday. He wrote:

It is emphasised here that the present report expresses a viewpoint which is contrary to themainstream scientific theme currently reinforced through various USagencies in the wake of recent major findings under US leadership (egthose of Luis Alvarez, Eugene Shoemaker, David Morrison etc. Despitethe importance of this mainstream theme, it is recognized here that thecometary signatures in the terrestrial record are generally strongerthan the asteroidal signatures in the case of both long term and shortterm effects ie those affecting biological and geological evolution onthe one hand and mankind and civilization on the other. The raison d'etrebehind this situation is a cometary input dominated in the long term byobjects > 100 kilometres in size which substantially break up in theshort term into objects < 1 kilometre in size, the "window" ofsignificance so far as the average interval between random impacts bycomets and asteroids in the intervening size range are concerned beingapproximately 1- 10 million years. To concentrate, for planetarydefence purposes, on catastrophes which occur only within thisparticularly narrow range of frequencies is patently absurd.

Clube's reference to the "mainstream scientific" ideas about cometsand asteroids and so on is only the tip of the iceberg in reference tothis debate.

The debate is about asteroids vs. comets. Asteroids are solid bodiesof rock and there are about 1000 of them with diameters of 1 km or morethat cross the orbit of the earth. They are called "Apollo" or "earthcrossing" asteroids. The "American School" of astronomers believe thatthese objects are the main threat to earth and humanity and they areconcerned with finding them, tracking them, and working out theirorbits. This school believes that if all these asteroids can be mapped,and any "bad ones" dealt with, Earth will be safe for the foreseeablefuture. Their estimates are that we only get hit with one of thesebabies about every 100,000 years or so.

At this point in time, the American school of astronomers hasalready found and tracked about 700 of the estimated 1000 suchasteroids and, so far, none of them are likely to hit the earth anytimesoon. By the end of 2008, they expect to have located 90% of thesepotential threats.

Of course, they aren't talking about objects smaller than 1 kmbecause they are believed to pose much less risk even if they do smackinto the earth.

So it is that the "American School" believes that they can, overtime and with superior American technology, survey everything around usand keep our space in space "under control."

What they are saying, as Baillie astutely points out is this: Thereare objects that cross the path of the earth but they hardly ever hitus (only about every 100,000 years), but they are going to make us safeby finding any and all of them and devising methods to take out theones that MIGHT pose a threat at any point in the future. They assume,of course, that if they figure out that any of them might be a threatby mapping their orbits, they will have time to do this.

In "Asteroid Astronomer World" there have not been any seriousimpacts in the last few thousand years, for sure, and they are going tosee to it that it stays that way!

How typically American! Don't you worry, little Lady, John Wayne andhis gang will circle the wagons and shoot up those redskins/outlaws!

It's obvious that Victor Clube is not a member of the American School.

The "Comet Hazard" school is British based and they think very differently from the American "mainstream" asteroid school.

Comets are said to be different from asteroids because they are madeup of water ice, frozen gas, organic materials, and odd bits of rockand metal. The standard theory (which may need revision according tothose who advocate the electric universe theory) says that comets areheated as they pass through the solar system and this causesoutgassing. It is then that we see them as bright objects with longtails.

After a few circuits through the solar system, some comets "outgas"completely and all that is left is a "very black lump" of any size,typically at least a few kilometers in diameter. The reason a worn outcomet is so black is possibly due to the poly-aromatic-hydrocarbonsthat are concentrated onto the comet's surface like a coating of tar.Such objects, unlike asteroids, are very difficult to spot because theydo not reflect light.

Comets also leave trails of dust and debris in the inner solarsystem and the Earth passes through such periodically. When thishappens, there are generally meteor showers which are really particlesof comets burning up in the atmosphere.

Comets can also break up in to smaller - but still sizable - chunks.

Now, imagine that in a trail of comet dust, there are also somefairly large chunks of black, un-seeable, comet fragments. If you can'tsee them, you can't do anything about them. And when they do "hit,"they tend to burn up and/or explode violently in the atmosphere (egTunguska event), so they don't leave long-lasting traces such ascraters for archaeologists to find and say "Yes, the fall of thiscivilization was due to an assault from outer space." No, there is onlyfire, death and destruction; sometimes total.

What all this means is that the comet problem does not submit itself to an efficient solution.

The Comet Hazard school scientists propose that the Tunguska event was due to a fragment of Comet Encke.These scientists also now have the FACT of the fragments of CometShoemaker-Levy hitting Jupiter in July of 1994 to illustrate theproblem we face. The Comet Hazard scientists also think, as mentionedabove, that impacts are a lot more frequent than many people suppose.

So, to sum it up: there are two very different schools that studyhazards from space. The Asteroid school says that there have been veryfew impacts and the problem is solvable, and the Comet school saysthere is evidence that there have been numerous impacts by comet debristhat have had profound effects on human civilizations, and will again,probably very soon.

Okay, now let's take a look at Victor Clube's summary of the problem. He writes:

Asteroid strikes, though important, are not the most serious short-term risk to mankind or civilization

Every 5-10 generations or so, for about a generation, mankind issubject to an increased risk of global insult through another kind ofcosmic agency.

This cosmic agency is a "Shoemaker-Levy type" train of cometarydebris resulting in sequences of terrestrial encounters with sub-kmmeteoroids.

Subsequently perceived as pointless, such transitions are commonlyan embarrassment to national elites even to the extent that historicaland astronomical evidence of the risk are abominated and suppressed.

Upon revival of the risk, however, such "enlightenment" becomes aninducement to violent transition since historical and astronomicalevidence are then in demand.

Such change and change about in addition to the insult is evidentlyself-defeating and calls for a procedure to eliminate the risk.

The very short lead-time commonly associated with the detection ofsum-km meteoroids approaching the Earth implies countering procedureswhich differ from those associated with catalogued km-plus asteroidsand comets.

So, the question is: if there is even a 10 % chance that we arefacing a Shoemaker-Levy type event, why isn't anybody doing anythingabout it?

Well... maybe they are. Maybe all this War on Terror business andgetting control of resources is, at its root, the psychopath's way ofhandling a threat to their survival. Maybe it isn't the "Twilight of the Psychopaths" as Kevin Barrett might like to think... but the Twilight of Humanity; if we don't wake up.

A small but growing number of astronomers are arguing that the risksof comets or meteors hitting Earth are much higher than past estimatessuggest.

Some of these objects may be going unnoticed in space, theresearchers say, and scientists may need to begin new studies tailoredto finding them.

But advocates of the earlier estimates are shooting back that the evidence doesn't warrant revising the figures drastically.

The traditional estimates, based on sky surveys and other techniques, vary.

But in general, they conflict with the number of objects actuallyfound to have visited Earth's neighborhood, according to David J. Asherof the Armagh Observatory in Northern Ireland and three colleagues.

These numbers may provide better estimates, they wrote in theOctober issue of the research journal Observatory, because they"represent observational 'ground truth' so far as impact statistics areconcerned."

To re-estimate risks from these limited data, the team made a simple - but to some critics, questionable - assumption.

Basically, if a given type of object struck once in the past twocenturies, they assumed it hits once every two centuries on average. Asomewhat longer, but essentially similar calculation translated knownnear-misses into impact probabilities.

They analyzed in this way three well-studied types of object eitherseen to have passed near Earth or believed to have hit recently. Theyalso took into account other flybys whose occurrence they deduced frommeteorites.

Their revised estimates in the Observatory paper were as follows:

* Impacts greater than 10 megatons (about 500 Hiroshima bombs),like a 1908 explosion in remote Siberia widely attributed to a spaceobject, would occur at least every 300 years. That's almost tenfold therate generally accepted estimates suggest. The blast in Tunguska,Siberia, felled an estimated 60 million trees.

* Strikes of a hundredfold greater destructive energy or more wouldhappen every 3,000 years or so, more than 10 times as often asprevailing estimates.

* Objects known as active comets packing a 100-million-megatonpunch - an event like what may have killed off the dinosaurs along withmore than half the Earth's other species - would strike once every fewtens of millions of years. That's about 100 times more often than aconventional figure of every 3 billion years. The team didn't presentrevised estimates for another class of comets, inactive comets, thoughtto hit every 150 million years or so.

"We're not trying to make a precise estimate," Asher said. "We'retrying to point out that if you accept all the current estimates, thenthe three or four single objects we've mentioned," these together don'tfit prevailing views.

The work was in part a follow-up on earlier findings by researchersat Cardiff University in Cardiff, U.K., one of whom also co-authoredthe Observatory paper.

The earlier study, which appeared in the Nov. 2004 issue of theresearch journal Monthly Notices of the Royal Astronomical Society,proposed that most potentially dangerous comets are unseen becausethey're too dark.

But some astronomers are skeptical of all this.

Donald K. Yeomans of NASA's Jet Propulsion Laboratory in Pasadena,Calif., wrote in an email that Asher's team employed what he called"the statistics of one," the unreliable practice of drawing statisticalconclusions from one object.

Asher countered that although he sometimes used one object torepresent a class of objects, he repeated this for several differentclasses, with similar results. "It seems to be stretching theimagination to say they're all just coincidences," he said.

Yeomans, lead author of a major 2003 NASA report on the impactrisks, also said any dark "stealth comets" would emit strong infraredlight, a type of light invisible to the eye. Past space surveys wouldhave detected this, he added. Asher said those surveys haven't beenextensive enough, and wider ones may be warranted.

In any case, Yeomans said, not all past assessments have been asrosy as the ones Asher's team criticized. His own report, Yeomansargued, contains numbers that aren't as far from those of Asher asother papers are.

Asher conceded at least one point: his study doesn't explain just why all these objects would be going unseen.

Yeomans argued that all known comets have nearly the samereflectivity, which largely determines their brightness, and that thesedata contradict the dark comet proposal. Asher acknowledged the lack ofknown dark comets is puzzling in the context of his study, butsuggested something else may explain why objects are going unseen.

One possibility is that they're breaking up into smaller,less-noticeable pieces, he added. Either way, he wrote in an email,"there remain unsettling discrepancies in our understanding of thesematters."

These clouds may provide the clearest indication of the impact locations after each event.

Large regular fluctuations of atmospheric temperature and pressurewill be created by the shock front of each entering fragment and traveloutward from the impact sites, somewhat analogous to the ripplescreated when a pebble is tossed into a pond. These may be observablenear layers of existing clouds in the same way that regular cloudpatterns are seen on the leeward side of the mountains. Jupiter'satmosphere will be sequentially raised and lowered. creating a patternof alternating cloudy areas where ammonia gas freezes into particles(the same way that water condenses into cloud droplets in our ownatmosphere) and clear areas where the ice particles warm up andevaporate back into the gas phase.

Whether or not these "wave'' clouds appear, the ripples spreadingfrom the impact sites will produce a wave structure in the temperatureat a given level that may be observable in infrared (or thermal) maps.In addition there should be compression waves, alternate compressionand rarefaction in the atmospheric pressure, which could reflect andrefract within the deeper atmosphere, much as seismic waves reflect andrefract due to density changes inside Earth.

The phenomena directly associated with each impact from entry trailto rising fireball will last perhaps three minutes. The fallback ofejecta over a radius of a few thousand kilometers will last for aboutthree hours. Seismic waves from each impact might be detectable for aday, and atmospheric waves for several days. Vortices and atmospherichazes could conceivably persist for weeks. New material injected intothe Jovian ring system might be detectable for years. Changes in themagnetosphere (Jupiter's magnetic field is much stronger than that ofEarth and affects an area of space tens of millions of kilometers fromthe planet) and/or the Io torus (particles ejected from Io's volcanoesare ionized and trapped by Jupiter's magnetic field into a donut-shapedtorus completely circling the planet) caused by the sudden influx oflarge amounts of cometary dust might also persist for some weeks ormonths. There is the potential to keep planetary observers busy for along time!

What observations are astronomers planning?

Many large telescopes will be available on Earth with which toobserve the phenomena associated with the Shoemaker-Levy 9 impacts onJupiter in visible, infrared, and radio wavelengths. Apart from theobvious difficulty that the impacts will occur on the back side ofJupiter as seen from Earth, the biggest problem is that Jupiter in Julycan only be observed usefully for about two hours per night from anygiven northern hemisphere site. Earlier the sky is still too bright andlater the planet is too close to the horizon. Therefore, to keepJupiter under continuous surveillance would require a dozenobservatories equally spaced in longitude around the globe. A dozenobservatories is feasible, but equal spacing is not. There will be gapsin the coverage, notably in the Pacific Ocean, where Mauna Kea, Hawaii,is the only astronomical bastion. In the southern hemisphere Jupitercan be observed for longer periods of time for example, at 30 degreessouth latitude it will be visible for five hours. but only Australiaand Chile offer major observing facilities and it will be mid-winterthere.

There are at least four spacecraft -- Galileo, Ulysses, Voyager 2, and Clementine-- with some potential to observe the Jovian impacts from differentvantage points than that of Earth. There is also the Hubble SpaceTelescope (HST) in orbit around Earth, which will view the event withessentially the same geometry as any Earth-based telescope. HST.however, has the advantage of' no atmospheric turbulence, very lowscattered light, ultraviolet sensitivity, and the ability to observemuch more than two hours each day. HST is scheduled to devoteconsiderable time to the observation of Shoemaker-Levy 9 before as wellas during the impacts.

The Galileo spacecraft has the best vantage point fromwhich to observe the impacts. It is on its way to Jupiter and will beonly 246 million kilometers away from the planet, less than a third thedistance of Earth from Jupiter at the time. All of the impacts willoccur directly in the field of view of its high resolution camera. Inaddition, instruments that study infrared and ultraviolet light willmost likely be used.

Using Galileo to make observations will be challenginghowever. The amount of data the spacecraft can transmit back to Earthis limited by the capability of its low-gain antenna (the spacecraft'shigh-gain antenna, which could have transmitted large amounts of datain short periods of time, failed after launch and the time available onthe receiving antennas of NASA's Deep Space Network here on Earth. Alot of data frames can be stored in the Galileo taperecorder, but only about 5 percent of them can be transmitted back toEarth. so the trick will be to decide which 5 percent of the data aremost likely to include the impacts and have the greatest scientificvalue, without being able to look at any of them first! After the fact,the impact times should be known quite accurately. This knowledge canhelp to make the decisions about which data to return to Earth.

The impact site of the fragments of Comet Shoemaker-Levy 9 on Jupiter.

The Ulysses spacecraft was designed for solar study andused a "gravity assist'' for flying close to Jupiter to change itsinclination (the tilt of its path relative to the plane of the planets)so it can fly over the poles of the Sun. In July 1994 it will be about378 million kilometers south of the plane of the planets (the ecliptic)and able to "look'' over the south pole of Jupiter directly at theimpact sites. Unfortunately, Ulysses has no camera as a partof its instrument complement. It does have an extremely sensitive radioreceiver that may be able to detect thermal radiation from the impactfireballs once they rise sufficiently high above interference from theJovian ionosphere (upper atmosphere) and to measure a precise timehistory of their rapid cooling.

The Voyager 2 spacecraft is now far beyond Neptune and isabout 6.4 billion kilometers from the Sun. It can look directly back atthe dark side of Jupiter, but the whole of Jupiter is now only twopicture elements in diameter as seen by its high resolution camera, ifthat instrument were to be used. In fact the camera has shut down forseveral years, and the engineers who knew how to control it have newjobs or are retired. It would be very expensive to take the camera "outof mothballs'' and probably of limited scientific value. Voyager does have an ultraviolet spectrometer which is still taking data, and it will probably be used to observe the impact.

A new small spacecraft called Clementine was launched on Jan. 25 of this year, intended to orbit the Moon and then proceed on to study the asteroid Geographos. Clementinehas good imaging capabilities, but its viewpoint will not be muchdifferent from Earth's. Still. it seems probable that attempts will bemade to observe "blips'' of light on the edge of Jupiter from theentering fragments or subsequent fireballs.

Stupendous as these collisions will be, they will occur on the farside of a planet half a million miles from Earth. There will be nodisplay visible to the general public. Amateur astronomers may note afew seconds of brightening of the inner satellites of Jupiter duringthe impacts, and they might observe minor changes in the Jovian cloudstructure during the days following the impacts. In the best of cases,these events will be spectacles for the mind to imagine and bigtelescopes to observe, not a free fireworks display. The real value ofthis most unusual event will come from scientific studies of thecomet's composition. of the impact phenomena themselves, and of theresponse of a planetary atmosphere to such a series of "insults.''

Atmospheric phenomena on this scale cannot be reproduced, even bynuclear fusion explosions, and have never before been observed.Sixty-five million years ago the Earth was struck by a large asteroidor comet, an event which may have hastened the extinction of thedinosaurs. Better knowledge of the effects of Comet Shoemaker-Levy 9 onJupiter may allow scientists to predict more accurately just howserious could be the results of future impacts of various-sized bodieson Earth.

Energy Comparisons & Power Comparisons

Energy Comparisons

Event

Energy in Joules

Energy Relative

Two 3,500-lb. cars colliding head-on at 55 mph

9.6 X 105

1

Explosion of 1 U.S. ton of TNT

4.2 X 109

4,271

Explosion of a 20-megaton fusion bomb

8.4 X 1016

87,500,000,000

Total U.S. annual electric power production, 1990

1 X 1019

10,400,000,000,000

Energy released in last second of 1013-kg fragment of Comet Shoemaker-Levy 9

9 X 1021

9,375,000,000,000,000

Total energy released by 1013-kg fragment of Comet Shoemaker-Levy 9

1.8 X 1022

18,750,000,000,000,000

Total sunlight on Jupiter for one day

6.6 X 1022

68,750,000,000,000,000

+ Note: 1 BTU = 252 (small) calories = 1,055 Joules = 2.93 X 104 kWh.

Power Comparisons

Power Producer

Power in Megawatts

Power Relative

Hoover Dam

1,345

1

Grand Coulee Dam, final plant

9,700

7.2

Annual average, sum of all U.S. power plants

320,000

238

Average, impact of 1013-kg fragment of Comet Shoemaker-Levy 9, final second

From July 16 through July 22, 1994, pieces of an object designatedas Comet P/Shoemaker-Levy 9 collided with Jupiter. This is the firstcollision of two solar system bodies ever to be observed, and theeffects of the comet impacts on Jupiter's atmosphere have been simplyspectacular and beyond expectations. Comet Shoemaker-Levy 9 consistedof at least 21 discernable fragments with diameters estimated at up to2 kilometers.

Comet Shoemaker-Levy 9, torn into pieces as a result of a closeapproach to Jupiter in July 1992, will collide with Jupiter during thethird week of July 1994. Of tremendous scientific importance, theimpacts of the cometary fragments will release more energy intoJupiter's atmosphere than that of the world's combined nucleararsenals. Because the impacts will occur on the night side of Jupiter,the explosions will not be directly observable from Earth. However,professional and amateur astronomers may observe the impact lightflashes reflected off the inner satellites of Jupiter. Any lastingeffects on Jupiter, such as atmospheric clouds, ejecta plumes, orseismic thermal disturbances, may be observable an hour or so laterwhen the rotation of Jupiter brings the impact sites into Earth's view.

Analysis of high-resolution images of the comet taken by the NASA'sHubble Space Telescope in July 1993 suggests that the major cometaryfragments range in size from one to a few kilometers. The largefragments are embedded in a cloud of debris with material ranging insize from boulder-sized to microscopic particles. Although comet-likeoutgassing of the fragments has not been observed, the fragile natureof the object suggests that it is indeed a comet rather than a morecompact asteroid.

Comet Shoemaker-Levy 9 was the ninth short-periodic comet discoveredby Eugene and Carolyn Shoemaker and David Levy. It was first detectedon a photograph taken on the night of March 24, 1993 with the 0.4-meterSchmidt telescope on Palomar Mountain in California. Subsequentobservations were forthcoming from observers at the University ofHawaii, the Spacewatch telescope on Kitt Peak in Arizona and McDonaldObservatory in Texas. These observations were used to demonstrate thatthe comet was in orbit about Jupiter, and had made a very closeapproach (within 1.4 Jupiter radii from Jupiter's center) on July 7,1992. During this close approach, the unequal Jupiter gravitationalattractions on the comet's near and far sides broke apart the fragileobject. The disruption of a comet into multiple fragments is an unusualevent, the capture of a comet into an orbit about Jupiter is even moreunusual, and the collision of a large comet with a planet is anextraordinary, millennial event.

As we kick off the year 2008, Comet Tuttle is putting on a nice showfor backyard skywatchers. It had not been seen since 1994, but you'llhave an excellent opportunity to pick it up with binoculars or smalltelescopes during the next two weeks.

Tuttle can even be glimpsed by sharp-eyed observers under pristineskies without any optical aids, for it is one of the brightest of theshort-period comets, those that orbit the sun often enough to be seenagain and again from Earth and identified as such.

And speaking of short-period comets, Comet Holmes continues todelight observers more than two months after its stupendous explosionto naked-eye visibility.

Discovery

As we all know, Halley's was the first comet-to be recognized asperiodic, but it had been seen on many previous returns before EdmundHalley announced that fact in the year 1705. Similarly, althoughEncke's comet was discovered in 1786, it was observed on three morereturns before Johann Franz Encke determined that it had an orbitalperiod of 3.3-years.

The object that we today call Comet Tuttle had a similar history.

On Jan. 9, 1790, the renowned Parisian comet hunter Pierre Méchaindiscovered a fairly bright telescopic comet in the western evening sky.His friend and rival Charles Messier described it on the followingnight as resembling an unresolved star cluster or nebula without anucleus. It was followed for just over three weeks; just not enoughtime for a sufficient number of observations to determine an accurateorbit.

Astronomers assumed that the object was traveling in a parabolicorbit and would never be seen again, and entered the literature simplyas "Comet 1790 II." It wasn't to be seen again for nearly 70-years.

Tuttle's turn

Horace P. Tuttle, an assistant at Harvard College Observatory,discovered three comets by telescope during the year 1858. Tuttle foundthe first of them on Jan. 4 in the constellation Andromeda. Stillapproaching the perihelion point of its orbit (its least distance fromthe sun), the comet was favorably placed relative to the Earth, andthis made possible a long series of positional measurements.

Comet Tuttle was brightest during February at about magnitude 7,meaning it was just below the threshold of naked eye visibility, thougha relatively easy object to see with binoculars or a small telescope.

Tuttle himself was among the first to suggest that his object wasidentical with Comet 1790 II. A 13.7-year period was proposed byseveral astronomers, and it soon became clear that Comet Tuttle of 1858had been missed at four intervening apparitions. At three of thosereturns (1803, 1817, and 1844) it was too close to the sun in the skyto be seen, while conversely, in 1830 it should have been an easyobject in the morning sky but was somehow missed.

Comet Tuttle became the eighth comet to be recognized as a periodic object hence it is now designated as 8P/Tuttle.

The perihelion distance of 8P/Tuttle places it just outside of theEarth's orbit at 95.5 million miles (153.6 million kilometers). Also,around Dec. 22 of each year the Earth passes through the dusty trailleft behind by the comet from its previous visits. This encounter givesrise to an annual display of meteors known as the Ursids, which appearto diverge from near the bright star Kochab in the bowl of the LittleDipper.

Because 8P/Tuttle was observed at each return following its 1858rediscovery except in 1953, this time around will go down in the recordbooks as its 12th observed apparition. And as it turns out, thisapparition will be among its very best.

Where and when to look

On New Year's Day, 8P/Tuttle passed closest to Earth; a distance of23.5 million miles (37.8 million kilometers). Although it is now slowlymoving away from the Earth, it will continue to slowly approach thesun, passing closest to it on Jan. 27. Comets are most visible whenthey near the sun, which lights up material that boils off the comet.

So, during these next two weeks, the comet will hold nearly steadyin brightness at around magnitude 6. For those blessed with clear, darkskies far from significant light pollution, the comet might be evenglimpsed with the unaided eye. But good binoculars or a small telescopewill easily bring 8P/Tuttle into view if you know where to train them;it should appear as a small fuzzy star possibly sporting a faint,narrow tail.

The comet will be situated against the rather dim stars that composethe so-called "watery region" of the sky, passing through easternPisces (the fishes) into Cetus (the whale) during the night of Jan.6-7. On that night, it will lie not far to the west from one of thebrightest stars in Pisces: fourth magnitude, Al Rischa, located at thepoint where the two fish are tied. In fact, the name comes from theArabic word for "cord."

For the next couple of weeks both Pisces and Cetus can beconveniently found well up in the southern sky between 6 to 8 p.m.local standard time.

Comet 8P/Tuttle will appear to skid south in its orbit against thebackground stars of these two constellations. After moving throughCetus, 8P/Tuttle will pass into the dim, shapeless constellation ofFornax (the furnace) on Jan. 16. It will continue to plunge souththereafter, gradually becoming unfavorably placed for viewers in theNorthern Hemisphere, although those living south of the equator will beable to follow the now fading comet right on into February.

A reminder about Comet Holmes!

While the spotlight is now on Comet Tuttle, we should not forgetabout our old friend, Comet Holmes which continues to be dimly visibleto the unaided eye as a diffuse, circular cloud, roughly twice theapparent diameter of the moon against the stars of the constellationPerseus.

This comet was no brighter than magnitude 17 in mid-October - that'sabout 25,000 times fainter than the faintest star that can normally beseen without any optical aid. But late on Oct. 23, the comet'sbrightness suddenly rocketed all the way up to magnitude 2.5,brightening nearly one million times in less than 24 hours!

In attempting to explain why Comet Holmes exploded, comet expert,John Bortle suggested that this comet's nucleus consists of low-densitymaterial that, over time developed into a large region with a verytenuous structure, like a honeycomb. At some point, the highly fragilebonds connecting the honeycomb of material reached a failing point anda sudden crushing collapse occurred, expelling a gigantic volume ofdust into space, making this dim comet suddenly appear impressivelybright.

Back in 1892, Comet Holmes suffered two major outbursts separated byabout 75 days. This leads to the question as to whether this comet willundergo a similar "cosmic aftershock" in the wake of its recent lateOctober explosion.

Bortle thinks it's a possibility, based on the theory that there maybe a large amount of residual instability which might lead to a secondmajor collapse of material on the comet nucleus. If what happens nowparallels what happened in 1892, another possible explosive outburstmay be imminent, so it might be wise to keep a close watch on CometHolmes in the coming days ahead.

On December 24, 2007, the website Space.com published a report entitled, "The Enduring Mysteries of Comets."The premise is intriguing, since it is rare for science media toacknowledge that "mysteries" of any real significance exist forconventional theories. Unfortunately, the report mentions few of therecent discoveries that have thrown the popular "dirty snowball" modelof comets into disarray.

"We have now had four close encounters with comets, and every one ofthem has thrown astronomers onto their back foot." -Stuart Clark, New Scientist, September 09, 2005.

The Space.com article begins with the statement, "Formillennia, comets were believed to be omens of doom." This itself is aprofound anomaly left unanswered by mainstream theorists, but theauthor makes no inquiry into why this is so. Instead, his next sentencereveals that the veil of discredited theories distorting scientists'view of comets has yet to be lifted. "...Solving the mysteriesregarding these 'dirty snowballs' could help reveal the part theyplayed in the birth of life on Earth, as well as secrets concerning therest of the galaxy." But as we shall see as we continue, one can onlyhold to the idea of comets as "dirty snowballs" by ignoring all of therecent revelations about comets.

The first item asks, "Did comets help create Earth's seas?" Thereport reads: "For years scientists thought comets slamming against thenewborn Earth helped deliver water to a once dry planet. But roughly adecade ago this view was shaken by the discovery that the water incomets and Earth's oceans did not match up in terms of hydrogenisotopes."

But the mainstream is not yet ready to abandon the notion ofprimordial comets dumping copious amounts of water onto Earth. Thearticle continues: "In the last two years, however, researchers havediscovered comets in the outer part of the asteroid belt. These'main-belt comets' may have the right levels of hydrogen isotopes, andare perhaps close enough to Earth to have realistically brought us theseas that life emerged from."

In the minds of Electric Universe proponents, most cometologistshave a distorted view of cometary water/ice. Cometary comas often exudean abundance of what scientists interpret as "water." In fact, whatthey measure as "water" is the hydroxyl radical OH, the most abundantcometary radical, which they assume is formed by the breakdown of waterfrom solar UV radiation. It is this radical's presence that leads totheir estimates of the amount of water ice sublimating from the cometnucleus.

Electrical theorist Wallace Thornhill offers a differentinterpretation, consistent with the surprising discoveries of recentyears. He notes that space probes have detected the negatively chargedoxygen atom, or negative oxygen ion, close to cometary nuclei.Additionally, spectral analysis of neutral oxygen (O) shows a'forbidden line' indicative of the presence of an 'intense' electricfield. Negative ions near a comet nucleus puzzled investigators becausesuch ions are easily destroyed by solar radiation. Thus, investigatorsreviewing the findings at comet Halley noted, "an efficient productionmechanism, so far unidentified, is required to account for the observeddensities" of negative ions.

As stated by Thornhill,"...the intense electric field near the comet nucleus is inexplicableif it is merely an inert body plowing through the solar wind." But theelectric model resolves the mysteries: "The electric field near thecomet nucleus is expected if a comet is a highly negatively chargedbody, relative to the solar wind. Cathode sputtering of the cometnucleus will strip atoms and molecules directly from solid rock andcharge them negatively. So the presence of negative oxygen and otherions close to the comet nucleus is to be expected. Negative oxygen ionswill be accelerated away from the comet in the cathode jets and combinewith protons from the solar wind to form the observed OH radical atsome distance from the nucleus."

If Thornhill is correct, the OH does not require water ice on, orin, the comet. Though it would be irrational to categorically excludethe possibility of ice, our probes have revealed scorched surfaceslooking more like burnt rocks than "dirty snowballs." They are, infact, barely distinguishable from ice-free asteroids.

The Space.com report continues with questions about theorigins of comets -- "Where do they come from?," and "Secrets regardingthe birth of the solar system?" Astronomers have long told us thatcomets were born in the theoretical "Oort cloud," about 4.6 trillionmiles from the Sun. Until fairly recently it was as simple as that. Buta few years ago, cometologists began to adjust the theory, postulatingthat only long-period comets were born in an ultra-remote cloud.Scientists have not reached a consensus on where they thinkshort-period comets originate. "Maybe there are other reservoirs ofcomets yet to be discovered," says astrophysicist David Jewitt.

Proponents of standard theory have long claimed comets are "Rosettastones" that can help us decipher the origins of the solar system. Butthe notion was dealt a devastating blow by the findings of NASA'sStardust Mission. The tiny fragments of comet dust that the missionbrought back to Earth did not accrete in the cold of space, but wereformed under "astonishingly" high temperatures. Mineral inclusionsranged from anorthite, which is made up of calcium, sodium, aluminumand silicate, to diopside, made of calcium, magnesium and silicate.Formations of such minerals requires temperatures of thousands ofdegrees.

NASA curator Michael Zolensky said, "That's a big surprise. Peoplethought comets would just be cold stuff that formed out ... wherethings are very cold....It was kind of a shock to not just find one butseveral of these, which implies they are pretty common in the comet."

Researchers were forced to conclude that the enigmatic particlematerial formed at a superheated region either close to our Sun, orclose to an alien star. "In the coldest part of the solar system we'vefound samples that formed at extremely high temperatures," said DonaldBrownlee, Stardust's principal investigator. "When these mineralsformed they were either red hot or white hot grains, and yet they werecollected in a comet, the Siberia of the Solar System."

Some scientists speculated that perhaps something occurred in orvery near the Sun in its formative phase, flinging immense quantitiesof material out to the periphery of the Sun's domain (far, far beyondthe orbit of Pluto), all the way to the Oort cloud. Then theresearchers reminded themselves that this would produce a mixing andcontradict the zoning that is evident in the asteroid belt. "If thismixing is occurring, as suggested by these results, then how do youpreserve any kind of zoning in the solar system," Zolenksy asked. "Itraises more mysteries."

But today, a new report states, quite unequivocally, that parts of Wild 2 formed in an area close to the Sun. The spacedaily.com site writes: "The X-ray and isotopic analyses point to gas acquisition in a hot, high-ion flux nebular environment close to the young sun."

The startling bottom-line is that comet scientists cannot give usany reliable story of comet formation. And the glaring contradictionsare barely acknowledged, if at all. The "mysteries" of the Stardustmission -- which are not mysterious under an electrical model of comets-- are not even mentioned in the Space.com report. Obviously,the question of comets' origins is profoundly affected by the discoveryof abundant minerals that only form under super-hot temperatures.

The Electric Universe puts forth a very different hypothesis on theorigins of both comets and asteroids. In an epoch of planetaryinstability in our solar system, many planets and moons, moving throughthe electric field of the Sun and immersed in an electrically dynamicenvironment, experienced electrical interactions with one another.Electric arcs shattered small moons and raked across planetarysurfaces, producing the most dramatic scarring features we see onplanetary bodies. These electrical scars include Valles Marineris, thestupendous chasm that stretches more than 3000 miles across the Martiansurface. In this view the comets and asteroids we observe are leftoversfrom these violent electric discharge events. And the composition ofcomets is from the same material that planets and moons were formed.

In fact, this vision of the electrical theorists explains the next "mystery" in the Space.compiece, "Why are comets so close to the Sun?" The report reads, "Themain-belt comets are themselves a mystery. Until their discovery,researchers had largely supposed no comets could have lasted that closeto the sun without getting baked away after a few centuries ormillennia." But then again, if the electrical theorists are correct,comets have not been around for billions of years, not even millions ofyears. They are the residue of catastrophe in the recent history of thesolar system.

The Space.com story concludes by attempting to answer thequestion of speculative "Interstellar comets." It reads: "As our solarsystem formed, calculations predict the gravitational pull of theplanets would have scattered 90 to 99 percent of all comets that onceorbited the sun away toward the stars, never to be seen again. 'Ifevery star does that, you would expect some of their comets to cometoward us, but no such object has ever been seen,' Jewitt said."

This admission only reinforces the failure of the standard model,confirming that virtually nothing discovered in recent decades hasmatched theoretical expectations. But in electrical terms, the idea ofcomets wandering interstellar space was never a viable concept. Ifcomets are the remnants of electrical discharge activity within thesolar system, then their short-term and long-term orbits are theresults we should expect.

Space.com considers the above mysteries to be the greatestpuzzles for conventional comet theory. We can only urge them to morecarefully consider the following comet discoveries, none of which areexpected by a "dirty snowball" model, but which are both explicable andpredictable by the electrical one:

Cometary Jets

Supersonic jets have been seen exploding from comets' nuclei. Fromthe mainstream perspective, these jets are eruptions of subsurface gasand water from solar heating. But again and again, this theory has beenrefuted by observation. In the case of Comet Wild 2, some of its nearlytwo dozen jets emanated from the dark, unheated side of the comet.And as seems to be the case with most comet jets, they remained intactacross great distances -- they did not disperse in the fashion of a gasin a vacuum (an anomaly left unresolved, and not even addressed by mostmainstream theorists). Consider also the jets of comet Hale-Bopp, which began discharging (seven jets) while it was still too far from the Sun for a "snowball" to melt.

Amazingly, as far as back as the early 20th century, the Norwegianphysicist Kristian Birkeland demonstrated experimental evidence for theelectric comet theory. He was able to emulate cometary jets from acathode in a vacuum tube -- Birkeland wrote: "From a cathode ofgraphite there came long, steady pencils of light, which greatlyresembled the so-called eruptions or jets in comets." (See Comets: Kristian Birkeland's Theory)

From the Electric Universe perspective, comet jets arise from theinteraction between the electric charge of the comet and the solardischarge plasma. The comet spends most of its time far from the Sun,where the plasma charge density is low. The comet moves slowly and itscharge easily comes into balance with that region. On the other hand,as the comet approaches the Sun, the nucleus moves at a furious speedthrough regions of increasing charge density and varying electricalcharacteristics. The comet's surface charge and internal polarization,developed in deep space, respond to the new environment by formingcathode jets and a visible plasma sheath, or coma. The jets flare upand move over the nucleus irregularly, and the comet may shed and growanew several tails. Or the comet may explode like an overstressedcapacitor (see below), breaking into separate fragments or simplygiving up the ghost and disappearing.

Cometary discharging may also occur due to any disturbances of itselectrical plasma sheath as it passes through regions of varyingelectric potential. This seems to have occurred in the recent "totallysurprising" outburst of Comet Holmes 17P as it moved away from the Sun's domain.

Comets Breaking Apart or Exploding

The unexpected break-up of comets, some at considerable distances from the Sun, has long baffled comet investigators. In 1976, Comet Westnever approached closer than 30 million kilometers from the Sun. Sowhen the comet suddenly split into four fragments, astronomers wereshocked.

More recently, the explosive break up of Comet Linear in the summer of 2000 provoked even greater amazement. The event occurred well over a hundred million kilometers from the Sun.

In fact, eighty percent of comets that split do so when they are farfrom the Sun, according to Carl Sagan and Ann Druyan, authors of thebook Comet. Comet Wirtanen fragmented in 1957 a little inside the orbitof Saturn, and something similar occurred to Comet Biela/Bambert.

But other comets have approached much closer to the Sun and notbroken apart. The perihelion of the Great Comet of December 1680,studied by both Newton and Halley, was less than 100,000 kilometersfrom the Sun, but it did not split.

We can also point to the astonishing disintegration of CometSchwassman-Wachmann 3, whose catastrophic fate remains unexplained bythe scientific mainstream. Some proposed that the comet disintegrateddue to "thermal stress" resulting from the rapid transfer of heatthrough thousands of feet of insulating material -- somethinginconceivable even if one ignores the deep freeze of the vacuum throughwhich the comet is moving, with its sunward face continually changingdue to rotation. Other explanations included "the outburst of trappedvolatile gases," and the suggestion that the comet flew apart from"rapid rotation of the nucleus." One astronomer even proposed that thecomet "was shattered by a hit from a small interplanetary boulder."This is yet another instance where scientists' lack of considerationfor an electric model has left them unable to explain what they'reseeing.

Many other "mysterious" comet discoveries and observations of cometbehavior are best explained as electrical phenomena. These include:

The sharply carved relief of comets -- the exact opposite of what astronomers expected under the "dirty snowball" model;

The unexplained abilityof a relatively minuscule comet nucleus to hold in place a highlyspherical coma, up to millions of miles in diamater, against the forceof the solar wind;

Ejection of larger particles and "gravel" that was never anticipated under the idea that comets accreted from primordial clouds of ice, gas, and dust;

A short supply or complete absence of water and other volatiles on comets' nuclei;

The predicted occurrence of an advance flash prior to the impact of a projectile into the nucleus of Comet Tempel 1 (Deep Impact.)Recently, the journal Icarus published a report confirming that theadvance flash did indeed occur, "upstream" (and slightly off-course) ofthe projectile -- exactly as one might expect of an electric dischargejust prior to impact.

----------------------------

This article began with reference to the historic quote, "Mysteriesare due to secrecy." If a kind of tacit "conspiracy" exists amongstspace scientists, it is to never speak of cosmic electricity, despitethe overabundance of evidence for electrical activity in space. Sadly,mainstream astronomy seems still to be guided by the axiom, "If itdoesn't fit, you must forget!" But the puzzles will not be solved byignoring or downplaying them. And in increasing numbers, critics oftoday's standard theory are coming to agree that the key to resolvingthese unsolved mysteries is electricity.

This artist rendering uses an arrow to show the predicted path of the asteroid on Jan. 30, 2008, and the orange swath indicates the area it is expected to pass through. Mars may or may not be in its path.

UPDATE - As expected, scientists at JPL's Near-Earth Object Officehave further refined the trajectory estimate for asteroid 2007 WD5 andruled out any possibility of a Mars impact on Jan. 30. The latesttrajectory plot of the asteroid was made possible by adding topreviously obtained data some new data from a round of observationsacquired by three observatories on the evenings of Jan. 5 through 8.Based on this latest analysis, the odds for the asteroid impacting Marson Jan. 30 are 0.0 percent. The latest observations come from theGerman-Spanish Astronomical Center, Calar Alto, Spain; the Multi-MirrorTelescope, Mt. Hopkins, Ariz.; and the University of Hawaii telescope,Mauna Kea, Hawaii.

I'm starting to receive reports of a fireball southwest of Baltimore Monday evening. Here are two of them:

From Donna Caudle:"My husband and I weredriving last night (1/7/08) through Perry Hall, MD when we spotted ablue-green fall fireball speeding to some site not far from us ... Wewere traveling near the area of Magdlet Rd in Perry Hall and Joppa wasclosed for some accident. I would say we were facing north west when wespotted it falling the the direction of Carney or Towson. The time wasabout 8:50 pm last night ,Monday the 7th of Janurary "

And, from Jeff Ceccola, who has reported before:"Frank,I was lucky enough to see another fireball tonight (1/7/08). Twice in a2 months. I fear my friends are going to think I'm fibbing when I tellthem about this one.

This one was to the southwest, in front of the constellationCetus. It had a greenish hue, with a magnitude of about a -4, lastingno more than 3 seconds.

I was in West Chester, Pa., the event occurred about 8:40 PM.From my POV, it was to the SW at about a 30 degree angle, falling fromSW to W.

Since my first event, I've been doing a lot more star gazing andhave studied sky maps. I'm sure my increased interest is why I waslucky enough to see yet another fireball..

Let me know if anyone has seen this one. Look for you in the Sun. -Jeff"

If anyone else out there saw this object, please send me a comment.Be sure to include the time you saw it, where you were, which directionit was going relative to your location, any sounds that seemed toaccompany the event, and any other descriptive details you have. Here is more on what to include.

Never seen a fireball? Well, here's one in a terrific image capturedNov. 2, 2005, by Mark Vornhusen of Germany and published by NASA. It isNOT Monday's object. But if you got a picture of it, send it to me andI'll replace this one with yours.

The Greene County Sheriff's Department was investigating Saturdaynight a series of explosions heard over a 10-mile area west ofSpringfield.

According to Capt. Randy Gibson of the Greene County Sheriff'sDepartment, the department received "eight or nine calls" of explosionsin the area of Greene County EE.

"We got reports from as far away as (Missouri) 266 west of town andnorth to Willard of explosions and light flashes. Some were loud enoughto rattle windows at residences north of I-44 and some were barelyaudible.

"It's a bit of a mystery to us at this point," said Gibson, who saidhe heard the explosions himself from his home. "They did not sound likea sonic boom and there shouldn't be any blasting in that area."

He said he heard four very loud explosions and eight smaller ones.He said the first one occurred about 7:45 and they continued for about25 or 30 minutes.

"Willard Police officers heard them, and the 911 call center in the middle of town."

According to NASA, beginning each New Year and lasting for nearly aweek, the Quadrantid Meteor Shower can be witnessed across the nightsky for nearly all viewers around the world, though Monday's sightingin Central Florida has not been confirmed as being related this annualinterstellar phenomenon.

The term meteor comes from the Greek meteoron, meaning phenomenon inthe sky. Solarviews.com describes a meteor as a streak of lightproduced as matter in the solar system falls into Earth's atmospherecreating temporary incandescence resulting from atmospheric friction.This typically occurs at heights of 50 to 70 miles above Earth'ssurface. A meteorite is a meteoroid that reaches the surface of theEarth without being completely vaporized.

The International Meteorite Collectors Association offers extensiverecords which show occurrences of meteorites striking man-made objects,animals and even people! You can see a list of such events, includingone reported strike in Orlando in 2004, by clicking here.

There was pandemoniun yesterday as a loud explosion emanating from a heavy metal - like object rocked the city of Sokoto.

The object fell from an unknown location and landed at Mana Village,Sokoto South Local Government Council, at about 10:00p.m. Wednesdaynight, in the compound of one Bello Mohammed, creating extra ordinarylightning across the metropolis.

THISDAY gathered that residents were thrown into confusionwhen they saw an illuminated object moving before it laterexploded.Assistant Commissioner of Police in charge of CriminalInvestigations Department, Sir Clement Adoda, who confirmed theincident, said as soon as the incident occured, security personnelmoved swiftly to the village and located the shattered house.

He said the object is a Meteorite, which has completelydestroyed the roof of Mohammed's house, and went almost two meters deepinto the ground. Adoda also went with bomb disposal men who took the object to the state police command for further investigation.

He, however, said the police are yet to ascertain where the object came from. No casualty was recorded.

The 2007 Planetary Defense Conference was held March 5-8, 2007 atthe Cloyd Heck Marvin Center at George Washington University inWashington, D.C. The primary objectives of the meeting were: tohighlight current capabilities in Near Earth Object (NEO) detection,characterization and mitigation; to advance understanding of the threatposed by asteroids and comets and arrive at possible responses to anasteroid impact; and to consider political, policy, legal and societalissues that would affect our ability to mount an effective defense. Theconference followed a format similar to the 2004 Planetary DefenseConference, results of which are summarized in an AIAA Position Paper.

Copies of papers, presentation material, and videos of the presentations themselves are available at the conference web site.

Day 1 of the conference provided an overview ofefforts to discover threatening Near Earth Objects (NEOs), defined asasteroids or comets whose orbits have perihelia of less than 1.3Astronomical Units (AU), and the subset of NEOs that pose a moreimmediate threat to Earth, called Potentially Hazardous Objects (PHOs).PHOs are defined as asteroids and comets that pass within 0.05 AU ofEarth's orbit and are large enough to cause significant damage shouldone impact Earth (~50 meters in diameter and larger). Day 1 presentersalso discussed what we know about the composition and structure ofPHOs, how such characteristics are determined, and what has beenlearned from recent missions to, and observations of, asteroids andcomets. Briefings included a summary of the detection andcharacterization aspects of the recently completed study by NASA inresponse to congressional direction. Information was also presented onNEO/PHO populations, the potential increases in their rates ofdiscovery, and the variation of impact probability as the number ofobservations increases.

Presenters in Day 2 discussed techniques that couldbe used to deflect or otherwise mitigate a threatening asteroid and thedesign of deflection and mitigation missions. Presentations highlightedhow NEO composition and structure influence the effectiveness ofmitigation techniques, described slow-push and quick-impulse deflectionmethods, and proposed techniques that could be used to break athreatening object into small fragments. Presenters also gave anoverview of missions that have been proposed to actually test ourability to move an asteroid. Included in Day 2 was the presentation ofdeflection technique-related highlights of the NASA Report to Congress.4

Day 3 summarized recent work on consequences of animpact, including tsunamis and the overpressure developed during ahigh-speed entry into Earth's atmosphere. The latter work suggests thattreating airbursts as point-source explosions may not provide the mostaccurate estimates of surface effects from NEO entries. Likely,hypothetical reactions of disaster and emergency response agencies andthe public to warnings or to an actual impact were also highlightedusing lessons learned from recent hurricane and tsunami-relateddisasters.

On Day 4, the final day, a panel of expertsdiscussed topics such as legal issues associated with testing andimplementing deflection techniques, educational aspects of NEO impactprotection, and maintaining funding for an ongoing, long-term level ofeffort on detection, characterization and deflection. The panel alsoreported on ongoing efforts to develop an international decisionprocess for NEO deflection. A second panel, made up of session chairs,discussed key points raised in each session. Meeting attendees wereinvited to address both panels.

After the meeting, key points discussed by presenters andparticipants were distilled and refined by the conference's steeringcommittee and circulated to all conference attendees for comment anddiscussion. Resulting consensus findings and recommendations arecollected in this document.

2. Findings and Recommendations

While significant scientific and technological advances have beenmade since the 2004 conference and are ongoing, it is clear thatproviding effective planetary defense from Near Earth Objects andplanning for mitigation of an impact disaster are in their infancy.Specifically, the primary findings of the conference are that:

1. While our search and discovery efforts havesuccessfully found most of the large, "civilization-killer" 1-km andlarger objects, we are just beginning to find the much more prevalentand, for that reason, more frequently dangerous objects in the 140- to300-meter size range. An impact by an object in this size range couldoccur with little or no warning and could cause serious loss of lifeand property over a broad area.

2. Earth-based resources such as the Arecibo radarare critical for refining a PHO's orbit and providing basic informationrequired for deflection. Arecibo has an essential role in refining thethreat posed by PHOs such as Apophis.

3. Deflection of a threatening object is in theconceptual phase. We are just beginning to identify the optionsavailable to deflect an object and have yet to design or testtechniques that might be used. Further, we have yet to design completemissions to deliver one or more deflection devices, and have notconsidered what is required to assure a high probability of success foran overall deflection campaign.

4. There are serious technical, political, policy,legal and societal issues involved in deciding whether and how torespond to a threat of a NEO impact. NEO impacts have the potential tocause disasters that would equal or exceed anything ever faced byrecent civilizations. Moreover, this type of threat has never beenseriously considered by any agencies that would have responsibility forresponding. In addition, it is uncertain where responsibility forcoordination of all aspects of the NEO threat lies, from detection todeflection to impact aftermath.

5. Understanding, analyzing, and dealing with apotential NEO threat is an international problem demandinginternational cooperation. Considerable work is required to develop afoundation for international cooperation and action in all areasrelated to planetary defense. This foundation may extend beyond defenseand include benefits from international manned and unmanned spaceexploration.

The remainder of this White Paper provides background andrecommendations in five areas considered at the conference: Detectionand Characterization; Deflection Approaches and Missions; ImpactConsequences and Response; Political, Policy, Legal; and PublicPerception and Trust.

2.1 Detection and Characterization

Significant progress has been made in detecting and tracking NEOs,with about 4600 currently known compared to ~2700 in 2004. Similarly,the number of known PHOs was about 580 in 2004 and is currently about850. Presenters estimated that there could be over 100,000 NEOs,including 20,000 PHOs, once the smaller, 140-meter and larger objectsare added to the catalog. It was suggested that as many as 10,000 new140-meter class objects, whose Earth impact probabilities willinitially be non-zero, might be discovered in the next 20 years shouldan effort to discover and catalog these smaller objects proceed. Inaddition, some NEOs are binary in nature, and accompanying bodies arethemselves large enough to pose a hazard; these must also be includedin deflection plans.

The 270-meter diameter asteroid 99942 Apophis continues to be anobject of interest, and the calculated probability of impact has variedas additional tracking data have been utilized to refine its orbit.Presenters discussed the predicted 2029 close Earth flyby and theassociated "keyhole," the small region in space during the 2029approach where Earth's gravity would perturb the asteroid's trajectorysuch that the subsequent 2036 encounter would be an Earth impact. Adeflection effort for Apophis prior to the 2029 keyhole would requiremore than four orders-of-magnitude less momentum transfer than after2029, and good tracking data during the 2012-2013 apparition of Apophisis particularly critical for refining impact probabilities and decidingwhether a deflection action is required before the 2029 close approach.As a note, there may be several deflection techniques, includingslow-push techniques, that could be applied prior to 2029; after thatdate, deflection options narrow to more energetic techniques - probablynuclear explosives. The Arecibo radar, which is scheduled for possibleclosure, is the most powerful instrument available for improvingorbital accuracy and physically characterizing many NEOs making closepassages to Earth.

A related issue is bringing appropriate assets to bear in acost-constrained environment. For example, the NASA report to Congressnoted that there are civil and U.S. Department of Defense assets thatcould be leveraged for the NEO detection task. There may also beinternational resources that should be integrated into these efforts.

One potential requirement for PHOs might be "tagging" the object topermit precise tracking for several years. The Planetary Society isconducting a global competition for a mission design to place atransponder on an asteroid, with a $50,000 privately funded prize.Results from this competition should be studied as a first step forfuture considerations of tagging. This competition may be a model forencouraging creative ideas for other aspects of planetary defense.

There is continuing scientific uncertainty about the internalstructure of NEO objects, with spacecraft imagery indicating that somesmaller bodies are not solid, monolithic bodies, but so-called "rubblepiles" - accumulations of smaller objects and debris held together bylittle more than their own self gravity. These physical properties areimportant for assessing the effects and effectiveness of deflection andmitigation options. Missions to asteroids may be the only way suchissues can be resolved.

U.S. and Japanese missions to asteroids and comets are providinginvaluable information on these bodies. Presenters detailed results ofthe Japanese Hayabusa mission to asteroid Itokawa and the proposedEuropean Don Quijote mission. The Hayabusa spacecraft is returning toEarth in 2010, hopefully with small samples of Itokawa obtained when ittouched down on the asteroid's surface. Don Quijote is being planned tosend an orbiter to an asteroid, where it will observe the effects of akinetic impact on the object and on its orbit.

Recommendations

2.1.1.Immediately initiate actions to locatethreatening objects in the 140-meter to 1-km size range. Objectssmaller than 1 km, while certainly not "civilization killers," arelarge enough to cause local devastation and large loss of life. Perhapsmore significantly, objects of this class are much more likely tostrike Earth during future decades than are larger objects. The 1908Tunguska event, caused by the entry of a NEO estimated to be 30-50meters in diameter, leveled over 2000 sq km of Siberian forest - anarea larger than the Washington, D.C. metropolitan area. Currenttechnology limits our ability to detect and track many objects thissmall, but ground-based telescopes could, if adequately funded,discover and track a high percentage of potentially threatening140-meter class NEOs in a reasonable time at a relatively low cost. Theaddition of a space-based infrared survey telescope could significantlyincrease the discovery rate and provide improved estimates of NEO sizes.

2.1.2.Characterize Apophis and refine its orbitduring the 2012-2013 apparition. Asteroid 99942 Apophis is the firstknown and tracked NEO that will pass close to Earth and present a realthreat of impact within the next 30 years. The 2012-2013 apparitionpresents the opportunity to substantially improve orbital predictionsand determine whether the threat warrants future deflection action.

2.1.3.Support the operation of facilities criticalto NEO discovery, orbit determination, and tracking. Discovery andprecision orbit determination are the critical first steps incharacterizing a NEO threat and initiating a mitigation action.Facilities and capabilities for collecting and quickly processingdiscovery data are essential. The planetary radar at Arecibo is aunique national asset. The facility has the world's best capabilitiesfor determining the orbit of Apophis, as well as estimating its sizeand spin state, detecting accompanying bodies, helping resolveuncertainties in impact probability and projecting the scope of impactdamage. But plans call for this asset to be shut down and renderedunavailable during the 2012-2013 apparition of Apophis. Its use duringthis period is very important for determining whether Apophis will be aserious threat to Earth in 2036. A similar need for this or anequivalent asset will exist as additional new objects are discovered.

2.1.4.Initiate a program in collaboration withplanetary science objectives for the in-situ characterization of PHOs.The effectiveness of deflection techniques is strongly influenced bythe physical characteristics of the target NEO, yet we do not have agood understanding of the range of properties with which we might haveto deal. Characterization missions, related to both general andspecific threats, are required to provide insight into the nature ofthe objects we may need to deflect. Small and micro-spacecrafttechnology should be considered to reduce costs and enable multiplecharacterization missions. International collaborative missions toachieve these goals should be encouraged.

2.1.5.Release the full 272-page "2006 Near-EarthObject Survey and Deflection Study" to the public. This report containsmore detailed data and analysis supporting the NASA NEO Analysis ofAlternatives Report to Congress4 and is an excellent benchmark for thecurrent state of knowledge on NEOs and their discovery and deflectionoptions.

2.2 Deflection Approaches and Missions

Sometime in the future a credible NEO threat will be identified andactions will be required to prevent an impact disaster. As noted, weare very early in the development of technologies and techniques thatcould be used for such action.

Potential options identified in the NASA Report to Congress anddiscussed at the conference vary from slow-push techniques such as thegravity tractor and mass driver to more energetic impulsive techniqueslike kinetic impactors and nuclear explosives. Of course, technologicaldevelopment and verification is required for each, and the nuclearexplosive option also requires addressing substantial public andinternational concerns.

In addition to technology developments related to the implementationof a deflection technique such as a gravity tractor or nuclearexplosive, each option also has mission design-related issues that mustbe addressed. For example, in many cases a kinetic impactor willapproach the NEO at a very high relative velocity, and thus willrequire rapid, accurate, and autonomous trajectory control. Similarly,slow-push techniques require rendezvous and long-term operation eitherattached, or in close proximity, to the target NEO. All options alsohave limitations imposed by the availability of launch vehicles and thedemand for high reliability.

The 2004 conference discussed mission reliability and it was notedthat to achieve the overall objective of deflecting an approachingobject away from Earth with high reliability, a deflection campaignmight include multiple launches of the same vehicle design. Further,since a common fault might be present in a single mitigation approach,a deflection campaign might actually consist of deflection attemptsusing two or more independent techniques.

The possibility of synergism between two deflection techniques wasdiscussed from the perspective that a deflection campaign mightincorporate both a slow-push and a more energetic technique to increaseoverall reliability. Some noted, for example, that a deflectioncampaign might utilize a slow-push technique as primary, with a quick-impulse technique as backup; others suggested a quick-impulse techniqueas primary, with a slow-push used to "clean up" the results. Of course,the mission timeline, cost effectiveness and overall probability ofsuccess of the campaign will factor into related decisions.

In all cases, we must be able to determine a new orbit after (orduring, in the case of a slow-push technique) execution of a deflectionattempt. The time required for establishing a new orbit must beincluded in the overall mission design and features that might be usedto improve the accuracy of the post-execution orbit, such as placing atransponder on the object or maintaining a spacecraft on stationnearby, were proposed.

The possibility was also raised that a deflection action mightsuccessfully avert a specific impact, but might increase thepossibility of an impact at some future date. Design of a mission for aspecific deflection must consider and minimize this possibility.

Recommendations

2.2.1.Research, characterize and demonstratetechnologies associated with the most promising impulsive and slow-pushtechniques. Except for some technologies that might be used forimpulsive missions, very little work to characterize deflectiontechniques has been done. Research is required to move these techniquesfrom concepts to viable options for NEO deflection. Research shouldidentify technologies critical to each method. Research should alsoconsider approaches that might be synergetic and improve the overallcertainty of a deflection mission. Included should be microgravityexperiments to illustrate the response of NEO materials to impacts orto methods that might be used to attach or couple to the surface ofsuch objects in microgravity conditions (i.e., attaching transpondersor other instrument packages).

2.2.2.Identify and pursue opportunities todemonstrate potential deflection technologies during characterizationmissions that are in formulation or early development. At present,designers of deflection missions must allow for large uncertainties inthe response of a target NEO to a deflection attempt, and additionalresearch is required to increase confidence in our ability to predictand control the effectiveness of a deflection attempt. Compatibleopportunities during characterization missions should be identified todemonstrate potential deflection technologies (e.g., attachingtransponders, testing kinetic impactors, using low-impulse ion enginesand slow-push techniques, etc.). The European Space Agency's DonQuijote mission is an example of the type of mission that might be usedto characterize a NEO and to test deflection technologies.

2.2.3.Develop and document complete designs of adeflection campaign, including launch vehicle and payload requirements,ground support requirements, overall mission reliability, missiontimelines and milestones, and costs. Our ability to deliver adeflection option to a threatening NEO with a high probability ofsuccess must also be considered in detail. Results of these studieswould feed into an overall NEO deflection plan and help develop aroadmap for the architecture of a deflection campaign using current andnear-term technology and capabilities. This plan should be updated on aperiodic basis.

2.3 Impact Consequences and Response

Many small objects enter Earth's atmosphere on a daily basis and afew yield fragments that survive to reach the surface as meteorites.While some small object entries lead to airbursts and most areharmless, an otherwise harmless but brilliant bolide (fireball) in thewrong place could be mistaken for an attack, potentially causing adangerous response. Quick notification of such events, should they bedetected, would help avert such consequences.

Larger objects enter less frequently, but the effects increase assize increases. As noted earlier, the 1908 Tunguska event occurredafter an airburst of a 30- to 50-meter-diameter object, which causedwidespread devastation. The energy released had previously beenestimated in the range of 10 to 20 megatons. More recent estimatessuggest that the energy released could have been as low as 3 to 5megatons. An entry of this size is estimated to occur once every 1000years on average. The statistical likelihood of such an entry thiscentury is 1 in 10.

Based on responses to past disasters, predictions are that an impactwould result in initial confusion at all levels of leadership. The lackof understanding of the characteristics of a major impact event andimpaired command and control are likely to result in delayed initialresponse efforts and resulting additional loss of life and suffering.As noted by Michael Chertoff, Secretary, U.S. Department of HomelandSecurity, in his testimony to the Select Committee Hearing after theHurricane Katrina disaster: "This tragedy 'once again' emphasized howcritical it is that we ensure our planning and response capabilitiesperform with seamless integrity and efficiency in any type of disastersituation - even one of cataclysmic nature."

Recommendations

2.3.1.Conduct an Impact Response Exercise - awell-scripted and well-designed tabletop exercise, driven by improvedgaming, modeling and simulation resources to increase understanding ofthe evolution of an impact disaster and demands on response agenciesand communication systems. For many natural disasters, agenciesresponsible for assisting those affected conduct simulations involvingall segments of disaster response to identify issues and developsolutions. An unexpected NEO impact should be added to the set ofdisasters simulated. The disaster could be either from an ocean impact,where the effects could be experienced by a long expanse of coastlineand possibly affect several or many nations, or from a land impact. Thesimulation would focus on effects of a 50- to 140-meter class NEO, asize that would likely impact without warning. Ideally, the exercisewould involve all stakeholders that would be involved in a response,including local and national governments, military organizations,disaster responders, and members of the press.

2.3.2.Incorporate the NEO hazard into the mandatesof agencies, both national and international, that are charged withaddressing very large-scale natural and man-made catastrophes. Nationsshould assess the risk relative to natural and man-made hazards, andencompass the NEO response within existing national and internationalframeworks that address the more familiar hazards, ensuring thatemergency response capabilities are suited to dealing with NEO-relatedscenarios.

2.3.3.Conduct additional research to advanceunderstanding of the relationship between NEO size and eventconsequences. This relationship is critical for setting the lower limitof our detection efforts and making the decision to initiate adeflection campaign or other mitigation efforts. Previously, NEOexplosions above Earth's surface (events believed typical of a class ofsmaller NEOs) have been treated as point-source explosions. Newinformation indicates that the shock and flow field generatedthroughout the entry trajectory may be important contributors to groundeffects (tsunamis, etc.). Additionally, an impact could release anelectromagnetic pulse that could interrupt communications amongdisaster responders. We may not yet understand the complete nature ofthe hazard associated with PHO impacts and the dependence of impactconsequences on object size.

2.4 Political, Policy, and Legal

An asteroid impact could occur anywhere on the globe at any time, soplanetary defense has implications for all humankind. All nations onEarth should be prepared for this potential calamity and work togetherto prevent or contain the damage. That said, there is currently verylittle discussion or coordination of efforts at national orinternational levels. No single agency in any country hasresponsibility for moving forward on NEO deflection, and disastercontrol agencies have not simulated this type of disaster.

Providing funding over the long term was also seen as a challenge.Much of the work in virtually all areas of planetary defense has beendone on individuals' own time and initiative. There is a need forongoing studies and peer-reviewed papers to improve our knowledge inthis area, as well as to increase the credibility of the issue and thepublic's trust in our ability to respond. The reality is that NEOdeflection or disaster mitigation efforts may not be required fordecades or longer, so governments, which are focused on more immediateconcerns, may not be willing to commit sufficient recourses to thistype of work. Determining the appropriate level of this work andfunding such activities over the long term is seen as a major issue.

In addition, major legal and policy issues related to planetarydefense need to be resolved. An example is liability for predictionsthat prove false or deflection missions that only partially work orfail completely, resulting in an impact. Other examples include:

· A prediction is made that an impact may occurin a specific area, and residents and businesses that might be affectedleave. Are there liabilities associated with the loss in propertyvalues if the prediction is wrong?

· A nation makes a deflection attempt, but itfails to change the object's orbit enough to miss Earth. Is that nationnow responsible for the damage inflicted?

· A NEO threat demands the nuclear option, butpublic perception is that the possibility of a launch failure andsubsequent damage is more acute than the threat from the NEO. What arethe liabilities and political and policy implications associated with alaunch failure during a deflection mission?

These types of issues should be discussed and resolved before they are raised by a serious threat.

Recommendations

2.4.1.Develop an international protocol for use insituations when critical decisions relating to threat and disastermitigation are required. Given the global nature of the consequences,it is unlikely that one country will decide on its own whether to takeaction. There must be international involvement in decision-making andin whatever actions are decided. Discussions on how these decisionswill be made should begin while there is no specific threat. Principlesand protocols for the process of communication and dissemination ofinformation about potential impacts, and the implementation ofnecessary mitigation measures should be negotiated and agreed to at aninternational level. These protocols should identify roles andresponsibilities of key players and include a means to notifygovernments and the public of all hazards of a regional or globalnature.

2.4.2.Increase international collaboration onefforts aimed at detection and characterization, mission planning, andresearch related to deflection. One concept suggested is to establish aPlanetary Defense Coordinating Committee (PDCC) where nations candiscuss and coordinate research efforts at the technical level. Thegroup might be similar to the current Inter-Agency Space DebrisCoordinating Committee (IADC)[1] where space agencies of 11 nationsmeet to address the issue of man-made debris. The PDCC would bechartered to coordinate NEO research activities and provide technicalrecommendations supporting legal and policy decisions.

2.4.3.Develop and implement a mechanism to maintainfunding for critical technologies and efforts over the long term.Establishment of a trust fund or foundation should be considered toensure uninterrupted financial support for research related toplanetary defense.

2.4.4.Develop a framework for the use of nuclearexplosives for NEO deflection before a credible threat is identified.The nuclear option for NEO deflection is sure to raise concerns amongthe public and governments, but this option would be necessary for thelargest NEOs, or for NEOs that don't respond as predicted tonon-nuclear techniques, or for those discovered too late to utilizeother options.

2.4.5.Develop international agreements limiting theliability related to making impact predictions or to taking or nottaking action on a NEO threat. In its discussions about NEOs, theinternational community should develop agreements regarding specificlimitations of liability for taking or not taking actions, and formaking predictions about NEO threats. At present, there may bepotential liabilities related to specifying a threat and to taking adeflection action. For example, the mere forecast of an impact couldhave tremendous implications for the value of land and for businessesin the impact zone; a failed or ineffective deflection attempt couldresult in a subsequent impact and serious damage to the original threatarea or possibly another area.

2.5 Public Perception and Trust

Low probability disasters come to the attention of policy makers andbecome part of the national and international agenda as the result offocusing events. These are infrequent, sudden and harmful events thatbecome known to the public and to the government simultaneously. Asattention-grabbers, they initiate a push to "do something" aboutredressing the situation and preventing its recurrence. A hurricane,earthquake, major oil spill or technological catastrophe can generate a"spike" in interest that typically peaks in a few weeks in the mediaand in a few months in governmental deliberations and then dissipatesas other issues come to the fore. Typically it produces a two-yearwindow of opportunity for preparing for similar disasters, a windowthat closes slowly in the absence of another focusing event.

Progress occurs when there is an organized community of scientistsand policy experts who push for new legislation during the window ofopportunity. Such "policy entrepreneurs" have been highly successfulpromoting useful legislation following earthquakes, with the resultthat construction standards have improved consistently over the pasthundred years. For example, earthquake policy entrepreneurs wereinstrumental in the drafting of the National Earthquake HazardReduction Act (NEHRA) of 1977. The key is a motivated and organizedgroup of policy advocates that presses for efforts to mitigate thehazard and not just speed the flow of post-disaster relief.

While no NEO impact disastrous to society has occurred yet,significant NEO detections and even low-level threat warnings providewindows of opportunity for educating the public and decision makers onthe nature of this recently recognized problem. Additionally, majorprojects, such as developing a new NEO warning or mitigation system,may have focusing effects and further our mitigation efforts. Inpresenting risk, we must treat the threat seriously and act throughestablished protocols that are understandable by the public.

Recommendations

2.5.1.Engage and sustain the interest ofprofessionals and practitioners from the social and behavioralsciences. Even as effective detection and deflection strategies dependupon the best available knowledge from astronomy, physics, andengineering, effective warning and recovery depend upon utilizing thebest available knowledge from anthropology, psychology, sociology,political science, risk communication and related disciplines.

2.5.2.Develop a strategy for educating elected andgovernmental officials and the public on the nature of the NEO threatand what to expect in regards to NEO detections and warnings. Thestrategy should include ways to present sober, realistic assessments ofthe facts during periods of potential high risk and subsequent riskreduction efforts after refined orbit determinations are arrived at.The strategy should also consider enhancing understanding of ourcurrent abilities to discover threats and the potential for impacts tohappen anytime without warning. One suggestion is to provide or enhanceInternet sites to show how threats evolve and to illustrate possibleaction scenarios. A protocol for actions and notifications should bedeveloped for threats that exceed predefined thresholds.

2.5.3.Examine how social factors such as individualand group psychology, culture, and political and religious beliefsmight affect the decision to move forward on a NEO deflection effort.Individuals approach problems from a variety of viewpoints, and thesefactors are likely to be involved in discussions and decisions relatedto planetary defense and disaster recovery. Experts involved in NEOscience and technology must also be aware of these aspects of theproblem - particularly when they are informing the public, decisionmakers or potential funders about their research implications. Aperiodic survey on issues related to planetary defense may be a way totrack progress in public understanding.

3. Summary

The 2007 Planetary Defense Conference focused on the currentstate-of-the-art of planetary defense-related technologies and legal,policy, political, and public-response issues that would affect thedecision to mount a deflection campaign or to respond to a NEO-relateddisaster. The broad sponsorship of the conference indicates thatplanetary defense is increasingly being accepted as a legitimate issueand goal internationally and domestically.

The 19 recommendations presented in this White Paper are a result ofpresentations and discussions at the conference and subsequentinteractions among conference participants. The hope of participants isthat the recommendations contained herein will encourage serious,long-term efforts to develop and test technologies and to debate andenact policies that support protecting Earth from the threat of NearEarth Objects.

In 1982, two British astronomers, S. V. M (Victor) Clube and William Napier, published a book entitled The Cosmic Serpent. Clube and Napier suggested that the outer planets occasionally divert giant comets(more than 50 kilometers in diameter) into the inner solar system intoshort-period orbits. Debris from the resultant disintegration of thesegiant comets can adversely affect the environment of the Earth. Dustingcan block sunlight, resulting in globally cooler conditions. Impactevents in the super-Tunguska class may result in not only heavylocalized destruction but also the occasional "impact winter" or dustveil with global climatological effects.

Clube and Napier identified the progenitor of the Taurid complex assuch a giant comet whose injection into a short-period (about 3.3 year)orbit occurred sometime in the last twenty to thirty thousand years.The Taurid complex currently includes the Taurid meteor atream, CometEncke (the only known currently active comet in the Taurid complex),"asteroids" such as 2101 Adonis and 2201 Oljato, and copious amounts ofdust. All ten of the numbered asteroids in the Taurid complex appear tohave associated meteor showers and therefore are likely to be extinct comets masquerading as asteroids.

The effects of the disintegration of the Taurid progenitor objectin an Earth-crossing orbit should appear in the geological andclimatological record. Clube and Napier marshalled evidence for sucheffects in "The Cosmic Serpent" as well as their later book Cosmic Winterpublished in 1990. Clube and Napier, following in the footsteps ofearlier catastrophists, also sought evidence of catastrophic events inancient mythology and history. These authors have also written papersin standard peer-reviewed journals about the role giant comets play inconstructing a tenable physical theory of coherent catastrophism.

The giant comets normally reside far beyond the planets, in aspherical cloud surrounding the Sun, called the Oort cloud. There isalso evidence for a flattened disk of comets closer to the inner solarsystem, called the Edgeworth/Kuiper belt. What prompts members ofeither of these comet repositories to enter the realm of the planets?Clube and Napier suggest a galactic influence. The solar systemperiodically passes through the plane of the galaxy as the Sun (and thesolar system with it) orbits the galactic center. Each passage maydislodge giant comets and divert them closer to the Sun. The outerplanets, particularly Jupiter, may then perturb some of these giantcomets into orbits which enter the inner solar system. These comets,stressed both by gravity and by heat from the sun, may fragment into acloud of smaller objects with dynamically similar orbits.

Chiron offers a good example of a giant comet as called for byClube and Napier's giant comet hypothesis. Chiron is somewhere between148 and 208 kilometers in diameter. Currently Chiron's unstable"parking orbit" lies mostly between Saturn and Uranus. Chiron may endup injected into the inner solar system within a hundred thousandyears, or ejected from the solar system on a similar time scale. It isalso possible that Chiron has already visited the inner solar system.

The Taurid complex and the Kreutz sungrazer group are two familiesof objects which most likely represent the fragmented remains of twogiant comets in the current era. SOHO has recently discovered many new members of the Kreutz group which were previously unknown.

The Kreutz progenitor was injected into a retrograde orbit andattained the sungrazing state at a high inclination to the ecliptic.Hence the debris of its "children" does not pose a threat to the Earth.The Taurid progenitor on the other hand ended up in a short-periodlow-inclination prograde orbit. This is why the Earth can encounter itsdebris with potentially calamitous results.

What would happen should the Earth pass through the orbit of adisintegrating giant comet just before or after the comet passes thatsame point? Since larger fragments tend to cluster close to the nucleusof the comet, chances would increase that the Earth would be bombardedby these larger fragments. The severity of this comet fragment showerwould far exceed any ordinary meteor shower. Not only would "shootingstars" and bright fireballs caused by small debris appear, but so toowould large airbursts and possibly ground impacts. These would resultin significant destruction should they occur over an inhabited area. Ifa large enough fragment struck in the ocean -- say, 200 meters or so indiameter -- it would raise tsunamis even at a great distance that wouldsweep away coastal habitations.

Duncan Steel, a colleague of Clube and Napier, refers to thisprocess as coherent catastrophism. Widespread destruction derives fromthe coherent arrival of many impactors within a few days, as opposed tothe sporadic arrival of objects spread randomly in space. The showerrepeats for a period of years until the cometary orbit precesses sothat the Earth no longer encounters the dense part of the debris field.(Of course, sporadic debris unrelated to the disintegrating comet mayimpact at any time as well.)

I believe that coherent catastrophism, as enunciated by Clube,Napier, Steel, and their colleagues, provides the best physical modelfor recent astronomical catastrophes, although I do not necessarilyagree with all of their historical ideas.

For a contrary viewpoint you should read David Morrison's reviews of recent books and articleson the impact hazard which includes the books by Lewis, Steel,Verschuur, Cox and Chestek, Gribbin and Gribbin, Desonie, andBarnes-Svarney. Also available is a preliminary version of a review ofDuncan Steel's book by Clark Chapman.The final version appeared in the journal Meteoritics and PlanetaryScience, v.31 (1996), pp. 313-314. Morrison and Chapman stronglydisagree with the Clube/Napier/Asher/Steel idea of coherentcatastrophism.

A common criticism levelled against Clube et al's giant comethypothesis is that it uses a "Velikovskian" approach to mythologicaland historical evidence as a primary basis. It does not. Even shouldevery single one of the mythological interpretations offered by Clubeand Napier in The Cosmic Serpent or Cosmic Winter prove to beincorrect, this says nothing whatever about the correctness of thegiant comet hypothesis and coherent catastrophism. The correctness ofthese depends solely on physical evidence. Mythological evidence mightat best be supporting evidence. The same cannot be said of many otherversions of non-orthodox catastrophism, e.g., Velikovsky's, which seekto rewrite physics and astronomy based upon ancient myths.

Cambridge Conference Correspondence Menuprovides archived messages from this mailing list run by Benny J.Peiser of Liverpool John Moores University. The Cambridge list offers avenue for announcements about current topics and research intonear-Earth objects and historical catastrophism.

Tony Smith discusses the Taurid complex, possible timing relationships between Supernovae and comets, and more on his Cometsweb page. Hale-Bopp was a relatively large comet of twenty-five milesdiameter. This is not as large as the purported Taurid progenitor, orcomet Sarabat, which reached a magnitude of -3.0 and was visible forover six months in 1729 A.D. Sarabat is estimated to have been 50 km to100 km in diameter. See my astronomy pages for more links to sites about Hale-Bopp and other comets.

Comets And Disaster In The Bronze Ageby Benny J. Peiser was originally published in the December 1997 issueof British Archaeology magazine. Peiser discusses the possible role ofcosmic impacts in the widespread collapse of many civilizations around2300 BC.

The extracts from Victor Clube's paper "Giant Comets and their Role in History" which appeared in The Universe and its Origins edited by S. FredSinger (Paragon House, New York, 1990) emphasize the potential climaticeffects of the Taurid complex.

The Second SIS Cambridge Conference entitled Natural Catastrophes during Bronze Age Civilizations: Archaeological, Geological, and Astronomical Perspectives(sponsored by the Society for Interdisciplinary Studies) was held atFitzwilliam College, Cambridge, UK, July 11-13, 1997. This conferencebrought together "historians, archaeologists, climatologists andastronomers in order to discuss whether the 'giant comet' hypothesisbrought forward by neo-catastrophist astronomers such as Victor Clube,Bill Napier, Sir Fred Hoyle, David Asher, Mark Bailey, Duncan Steel etal. can be substantiated by the archaeological, climatological andhistorical record." Includes abstracts of the presentations. See Mark Bailey's review of the conference for more details.

The Dark Ages: Were They Darker Than We Imagined?by Greg Bryant originally appeared in UNIVERSE - Journal of TheAstronomical Society of New South Wales Inc.. Bryant reviews thepossible relationship between major accretion events from the Tauridcomplex and the AD 536 onset of the Dark Ages.

In fact, it is passing so close that you can see it for yourself(from a dark site, with a large telescope). At magnitude 14, you willneed a 12" diameter telescope to spot it as it passes through UrsaMajor (the Plough) this evening (you can plot its position from yourlocations using Tom's Asteroid Flybys Webpage).

But the worry is that it was only discovered 3 days ago, highlighting the difficulty of finding asteroids that are coming straight for us!

If an asteroid is larger than 100m, and is expected to pass theEarth within 20 times the Earth-Moon separation, then it is considereda potentially hazardous asteroid. Fortunately, none are expected to hitthe Earth at the moment, but new ones are being discovered on a regularbasis.

Abstract: Mankind'sessentially untroubled state of mind in the presence of comets duringthe last two centuries has been fortified by the overall relativebrevity of cometary apparitions and the calculated infrequency ofcometary encounters with planets.

During the course of the Space Age, however, the fact of cometarysplitting has also become increasingly secure and there is growingappreciation of the fact that mankind's state of mind can never bealtogether relaxed. Indeed a watershed in the modern perception ofcometary facts has evidently been reached with the most recent anddevastating example of cometary splitting, that of the fragmen­tationof Comet P/Shoemaker-Levy 9 and its subsequent bombardment of planetJupiter.

Thus there is a recognized tendency now amongst comets, especiallythose in short-period orbits, due to the occasionally excessive effectsof solar irradia­tion, planetary tides and small body impacts, whichgives rise to individual swarms of cometary debris, and it is theresulting repeated penetration of such dispersed swarms by our planetwhich apparently increases the danger to mankind from time to time.

Historically, the presence of such danger was drawn to mankind'sattention by the observed bombardments over several decades due to"blazing stars threatening the world with famine, plague and war; toprinces death; to kingdoms many curses; to all estates many losses; toherdsmen rot; to ploughmen hapless seasons; to sailors storms; tocities civil treasons."

The sense of cosmic destiny aroused by these bombardments evidentlyinvolved degrees of fatalism and public anxiety which were deplored byboth eccle­siastical authorities and secular administrations with theresult that acknowledged dispensers of prognosis and mitigation whoendorsed the adverse implications of 'blazing stars' (astrologers,soothsayers etc.) were commonly impugned and cen­sured.

Nowadays, of course, we are able to recognise that the Earth'senvironment is not only one of essentially uniformitarian calm, asformerly assumed, but one that is also interrupted by 'punctuationalcrises', each crisis being the sequence of events which arises due tothe fragmentation of an individual comet whose orbit intersects theEarth's. That even modest crises can arouse apprehension is knownthrough the circumstances of the nineteenth century break-up of CometBiela.

Indeed it seems that these crises are rather frequentlycharacterized by relatively violent (paradigm shifting) transmutationsof human society such as were originally proposed by Spengler andToynbee more than sixty years ago on the basis of historical analysisalone.

It would appear, then, that the historical fear of comets which hasbeen with us since the foundation of civilization, far from be­ing thereflection of an astrological perception of the cosmos which wasderanged and therefore abandoned, has a perfectly rational basis inoccasional cometary fragmentation events. Such events recur andevidently have quite serious impli­cations for society and governmenttoday.

Thus when cosmic danger returns and there is growing awareness ofthe fact, we find that society is capable of becoming uncontrollablyconvulsed as 'enlightenment' spreads. A revival of millenarianex­pectations under these circumstances, for example, is not so much anunderlying consequence but a deviant manifestation of the violentturmoil into which society falls, often to revolutionary effect.

I. INSPIRATION AND FOREBODING

Today science is more or less unquestioned as the primary body ofsystematic knowledge reaching us through observation and measurement.However, by making too much of the more passive aspects of this body ofknowledge, i.e. its reproducibility through repeated accuratemeasurement, it is possible to undervalue the significance of its moreactive aspects, i.e. the inductive insights or connecting links whichultimately give the overall system of knowledge its intrinsic strength.

Scientists, of course, are aware of these countervailing tendenciesand while recognising the care, patience and technical skill that arenecessary to sustain the reproducibility of systematic knowledge, theydo also draw attention to the need for a state of mind in researchwhich brings its practitioners to the point of insight andenlightenment.

Thus a picture for the overall development of knowledge seems now tohave emerged in which the network of connections between supposedislands of knowledge may be discontinuously and abruptly rearranged asthe islands themselves continuously grow and dissolve. Admittedly anyprecise description of these discontinuities remains somewhat elusive(Kuhn, 1962 cf. Lindberg, 1992) but there is no lack of archetypes suchas Archimedes and his well known cry of Eureka! from the bath as hepondered the problem of the specific gravity of gold.

Our ancestors indeed, who undoubtedly recognised the importance ofthis not so very subtle aspect of the acquisition of knowledge, wouldtend to describe an enchanted state of mind which from the veryearliest times was believed to have been brought on through the wilesand trickery of a serpent. In fact, a modern dictionary still tells usthat to be fascinated, the prerequisite to knowledge, is to be deprivedof the power to resist or to escape by the look or presence of atormentor, possibly a serpent. A mythologist would have littledifficulty with such etymology: thus it was the original all-pervadingchaos associated with the primeval (cosmic) serpent, whatever this mayhave been, which served as the principal exemplar down the ages of theturmoil out of which desperate new connections were once forged andwhich was accepted as naturally illustrating the critical path by whichnew scientific (mostly astronomical) knowledge was obtained.

In other words, the insights leading to true knowledge have longbeen thought of as being brought to human attention by some kind ofmesmerising process or cunning on the part of nature. That is, weobserve natural phenomena as to whose cause we wonder and by whoseeffect we are astonished. And it is through the perceived enlightenmentthat comes by joining such cause and effect that a fascination in, say,astronomical phenomena is believed to broaden our cosmic experience andthereby enrich our cultural heritage.

We may be fascinated of course in the sense of being enraptured andheartened, in which case we are in the habit of accepting the cosmicrealm as a source of inspiration and our culture as both soothing andennobling. However, we may also be fascinated in the sense of beingagitated and petrified, in which case it can also be that the cosmicrealm is a source of foreboding and our culture is both disturbing andintoxicating.

Of the essence here is the injustice to our past if we look back onthe sum total of mankind's cosmic experience and fail to recognize howthis has ennobled our culture. But equally, there is the unfairness toour future if we look back on this experience and fail to appreciatehow it has also overwhelmed our culture from time to time, e.g. throughour response to the intermittent incidence of celestial 'signs'. Themistake in fact is to suppose that inspiration and foreboding areuniformitarian and arise in equal measure at all times, rather weshould be aware of the possibility of a temporal sequence in thebalance of inspiration and foreboding; and of the timescale ofvariation from one extreme to the other which is tantalizingly beyondthe usual reach of direct individual experience. That is, for longperiods of time on Earth, generations can follow generations under theimpression that our cosmic environment is a continuous source ofinspiration only to be succeeded for a while by generations aware ofthe fact that our cosmic environment can also be an intense source offoreboding.

The point to be noted then is that there are positive and negative,both light and dark, sides to the inspiration provided by astronomicalphenomena in the past; and we seriously misunderstand human history ifwe suppose our celestial environment never impinges adversely upon theEarth.

Quite simply, the enlightened or supposedly uniformitarianview of nature these last two hundred years has diverted attention fromadverse celestial inputs and there is now a serious risk,especially from within the fastness of an ivory tower, thatinspiration's commonest inducement, the appeal to a sublime principle,will continue to press our cosmic perspective and our culturalendeavour towards some kind of paradisical extreme.

To achieve some kind of balance of course, it is probably necessaryto come down from the fastness of the ivory tower and to join themaelstrom in the courtyard below for it is only through grim humancontact, it seems, that we are more able to contemplate thepunctuational crises which continually threaten and sometimes afflictcivilization. There will be optimists, to be sure, who will trivializesuch crises and regard such balance as imbalance but, as a well-knownyet typical mentor of the last century (Proctor, 1875) once quoted,when troubles were about to befall men, "nation rising against nation,and kingdom against kingdom, with great earthquakes in divers places,and famines, and pestilences, and fearful sights", then "great signsshall there be from heaven".

The point Proctor makes of course is that our cosmicexperience has always had both its paradisical and its purgatorialaspects and it is mostly when the latter are in the ascendancy that ourcosmic experience rouses us from the opium of culture and plunges usinto the politics of despair. Thus it could be a twentiethcentury indulgence to suppose despondency under uniformitarianconditions cannot be further plumbed for such could be as nothingcompared to the depths of despair which have come with the mostsignificant cosmic events during recent millennia.

In this essay, we shall begin with a 'journalistic' perspective onthe contemporary politics of punctuational crises and then move on toevaluate the cosmic perspective which now seems to be forced upon us. Weshall come to recognize that the great signs from heaven were neverprimarily the eclipses and random comets which we hang on oursupposedly ignorant ancestors, rather they were the fireball fluxsurges whose nature remains as problematical for us as it was for them.

2. COMETS BY JOVE - A WARNING TO THE PRESIDENT'S MEN?

The unprecedented events on Jupiter during the summer of 1994 servedto quicken the pace of developments in space. There was clearlysomething awesome in those predicted encounters of comet pieces with aplanet which, had they occurred on Earth, would have resulted in a mass extinction.Very few could have failed to be moved by the prospect that futurecomet splittings might suddenly produce a similar impact hazard headingtowards the Earth which mankind would be unable to avoid.

This graph summarizes the flux of large meteors (variously known as 'blazing stars', 'providences' or 'fireballs') during the period 100 BC- 1900 AD as recorded by Chinese imperial astrologers. Note the occasional large surges lasting from decades to centuries indicative of highly entrained cometary/asteroidal debris (a. la Shoemaker-Levy!) in orbit around the Sun and, hence, an increased likelihood of multi- megaton events. While the fear of 'last times' associated with these surges is demonstrably a significant eschatological force, dictating the course of history to a greater extent than is now commonly perceived, (note the surges at the time of Christ and during the European Dark Age), it seems that the events were essentially spurned during the aftermaths of the seventeenth and eighteenth century surges, coinciding with the English and American Enlightenments, respectively. Also, by integrating large meteors according to month and century, (See Figure 1 below) we note that the surges largely take place during the months of July - August and October - November, indicative of a single broad stream (the Taurids) in which most of the observed fragmentations occur. It seems likely that the fear of 'last times' is a long-standing historical problem associated with the disintegration of a single large comet originally at the core of the Taurid stream.

Inevitably, so it seemed, there was an added sense of common purposeto mankind's contin­uing watch on space. Such a sense of purpose in'spacewatching' has frequently arisen in the past usually in a nationalcontext, and can he traced back to the very dawn of civilization: onethinks for example of the Sumerians (e.g. Frankfort et al., 1946), thenlater the Chinese (e.g. Schafer, 1977) and eventually perhaps theAztecs (e.g. Sejourne, 1957), all of whom are known to have confrontedthe cosmos at different epochs for many generations with the same airof realism and foreboding.

Nowadays, of course, it is the American nation which bearsthe brunt of this watch and ensures that the responsibility is takenseriously. As recently as 1990 for example, Congress waspressing space agencies for an assessment of the impact risk tocivi­lization. Congress however did not count on inertia within thescientific corpus giving rise to a characteristically sanguineinterpretation of the brief. Thus there is a kind of mindset afflictingthose who put order into the cosmos which also causes them to resentdisorderly intrusions. Disintegrating comets which suddenly appear inthe Solar System are of this nature and the reaction which is by way ofturning a blind eye to unwelcome visitations can often mean that thecommon purpose is blunted. Those who would have turned us awayfrom Galileo's tele­scope so many centuries ago were still able to turnus away from the unprecedented events on Jupiter during the summer of1994!

Even as the comet pieces arrived though there was movement withinthe corridors of power to revitalize the body scientific. Thus the USCongress or, more specifically, its House Com­mittee on Science, Spaceand Technology was evidently impelled to recommend an immediatestepping up of the Spaceguard program - NASA's pipeline project to assess the asteroid and comet threat to civilisation from space.

Reflecting what appeared to be a public pressure on dilatory spaceguardians the Committee's Chairman Representative George Brown, was tocomment to the New York Times (Aug 1, 1994) that "you're going to see this thing take off like a rocket. It's going to be easy to sell in Congress".

Later, of course, the excitement receded and we reached a period ofmore measured reflection. There was then a question mark over NASA'sfailure to anticipate cometary splittings and a degree of concernwhether this organisation's activities should have been oriented soexclusively to single body events. The latter in fact are rare; and tothe extent that the currently nominated space guardians may also havehad it in mind to exploit asteroids and comets as the largestaccessible resource in space, one could readily suppose that the morefrequent hazard due to the more numerous debris from cometarysplittings had been seriously overlooked.

However, in making its more measured judgement, it was more or lessinevitable that the House Committee would reckon in terms of balancingall of NASA's previously approved and currently perceived requirements.This essentially meant a watering down of the more immediate celestial threat. The question for Congress still remained therefore whether Spaceguard provided everything that the American public expected.

To understand what is going on here, we need to examine some of theSpaceguard programme (Morrison, 1992) details which have been tuckedaway in the fine print. Thus the Spaceguard Catalogue,when it is completed, will be over 90% asteroids. But some of theseasteroids will be dormant or dead comets - and herein lies the catch.For, during the next century, the probability of the pureasteroid threat to civilization being realized is only about one in athousand. Whereas the probability of the dead, dormant or active cometthreat be­ing realized during the same period - due to cometarysplitting - is more in the region of certainty.

The asteroid threat by itself therefore is not of the kindthat will give Congressmen sleepless nights; the comet threat on theother hand could well be of the kind that is a cause of public concern.

The point is that there are crucial physical differences betweenpure asteroids and comets which are a significant factor when wecalculate their respective threats.

Basically, for the asteroid threat to be realised, we need a directhit on our planet - truly a rare event. For the comet threat to berealised however, given that these objects break up and the debrissprays out around the parent orbit, we need only a relatively closeencounter to have some fraction of the original material impact theEarth - a reduced input of mass evidently but impacts neverthelesswhich are altogether more frequent and by no means negligible in theireffect.

The Catalogue then is not the only problem; we need also to considerwhen comets are going to fragment. Indeed with the benefit of hindsighton the comets by Jove, the situation for the President is now veryclear. He may be provided with a map of the world but that does nottell him where and when the next Rwanda is going to arise. Likewise, hemay be provided with a catalogue of asteroids and comets in theirvarious orbits but that does not tell him where and when the nextearthbound Shoemaker-Levy is going to arise!

There is a very definite sense therefore in which the current NASA plan is deficient in relation to the civilization hazard from spaceand lulls the American public into a false sense of security. One hasto recognize of course that astronomers are trained not to cry wolf inthe night and it is a matter of normal common sense that the paymasteris most comfortable if the catalogue on offer appears to provide enoughwarning whilst keeping down the cost. Unfortunately, this kind ofbashful timidity and mutual backscratching amongst scientists andmoneyspinners currently results in our not having a policy to deal with the most probable hazard from space, a situation which seems to provide the American public with rather less than it expects!

For what then should we prepare?

First, of course, there is no point in denying the usefulness ofSpaceguard for the ferocity of the asteroid threat, when it isrealised, is not in doubt - mankind could well be extinguished. It doesnot follow however that the more frequent cometary threat can thereforebe ignored on account of the greater modesty of its effects - for, inthis case, it is also worth noting that mankind could well not beextinguished!

Thus governments are not merely confronted with a general fear of global extinction but with that of localized extinctions, or holocausts, as well. In other words, we really need to know about the troubles that arise during the anticipation and the aftermath of any multimegaton eventsthat occur in the wake of a fractured comet (see Section 3.3). These,as we have noted, occur at intervals of a couple of centuries or so andat the very least now we have to consider the possibility ofone or more population wipe-outs or Chernobyl-like disasters on theurban to large nation scale, or a mini-ice age of global proportions.

Less frequently, at intervals of a millennium or so, we can expectthe incidence of such disasters to be substantially increased.

Obviously these are tantalizing rates for heads of state who feelthat there may be a risk and that to be forewarned is to be forearmed.But invariably, so it appears, the general tendency is to discount therisk with the result that civilization and society are usuallyunprepared. Thus, just as fifteenth and seventeenth centuryEuropean society apparently broke down in the presence of newlyfragmented comets, so it appears the emerging global village of ourpresent epoch could well break down in the presence of yet anothernewly fragmented comet.

What matters here is the extent to which society is convinced by contemporary 'experts' that the danger is real.

For example, the breakdowns during the centuries precedingReformation and Enlightenment occurred as apparent historicalcertainties concerning the incidence of 'providences' or 'blazingstars' were newly translated into the vernacular (i.e. from the Booksof Daniel and Revelation) and propagated uncensored from the pulpit(e.g. Thomas, 1971). In the future, it is more likely to be the deeperhistorical certainties which are gained from the latest scientificunderstandings of our astronomical past and which are then propagateduncensored through a modern communications network of even greaterpower!

The problem always with these hazards, like the occasional snowstormover England, is their rarity - the fact that pragmatic authoritieswill at present only handle them in accordance with circumstances, asthey arise. This wholly reactive mode means that the cometthreat is never going to be taken seriously until such post-detectionpanic as will occur due to the incoming cometary debris is fullyrecognized for what it may very well be.

Paradoxically though, the more skilled and informed thecivilization, the sooner in general the reality is appreciated and thegreater the opportunity there is for the subordinate and more reliantelements of society to become seriously unsettled.

Mankind is not extinguished of course and many parts of the globemay even escape physical blemish, but it is a matter of generalexperience, overlooked apparently by the American scientific community,that sustained public panic is a very effective leveller of civilizations, even to the extent that many societies are capable of becoming seriously unhinged.

Thus it is not obvious that even the mostadvanced societies will avoid social chaos without the most carefulpreparation in advance to counter the illusion of 'last times'.

In the past, it has always fallen to individual nations andtheir administrations to attempt to deal with the illusion throughcounter-propaganda. In the future it seems more likely that it willfall to the global village to attempt to deal with the illusion throughcounter-propaganda and it is by no means clear that any preparationsare yet in place.

History is more informative in respect of this problem than many might suppose. Even the word 'revolution'for example, in its more general usage today, seems to have acquiredits meaning in the past through the recognized effects of the orbitingdebris of a comet! Thus it is generally accepted that its connotationsignifying social upheaval was a sixteenth and seventeenth centurydevelopment arising out of its earlier (Copernican) connotationsignify­ing physical circulation. However it is perhaps not so widelyappreciated that the witchhunts and political upheavals of theseventeenth century in England - which modern authorities sometimeslook upon as archetypal in respect of the circumstances which generally give rise to revolution- were directly attributed by contemporaries to the unsettling effectsof an (ob­served) celestial circulation: these contemporaries speak ofcelestial signs which were deliver­ies of "God's providence" and whichwere evidently mediated by "God's revolution".

Indeed these types of attribution, once the signs had passed, werevery soon to mean that the blazing stars were scorned by the learned:Bishop Sprat (ed. Cope and Jones, 1959) in his History of the RoyalSociety speaks of a peculiar weakness on the part of his countrymen, tosupposed prodigies and providences, which was now no longer to beencouraged. Thus the demise of the London Society of Astrologersbroadly coincided with the transition from Interregnum to Restorationand the emergence of the Royal Society of London; and, it is apparent,also to a period of intense scientific censorship (Hill, 1975).

It is well known for example that very few of Newton's historicalresearches into catastrophism and the role of comets and fireballs werepublished in his time with the result that astronomical science, andhence natural philosophy, tended thereafter to assume uniformitarian(i.e. non-catastrophic) characteristics.

Neverthe­less, we can now tell from past astronomical records whencivilization was apparently unhinged by threatening signs in the sky(see Section 4.1) and it is clear that the cometary threat, on thepoint of being realised, is far from being a trivial occasion - ourancestors were not joking, it seems, when they saw disintegratingcomets as "a warning to kings".

Even the President's men therefore may need adegree of authority and understanding in the face of incoming cometarymaterial such as the age of 'enlightenment' has so far failed toprovide.

The point here, of course, is that modern society, like itsfounding fathers, chooses still to ridicule the cometary threat.Ridicule was necessary perhaps as the means to a particular end - therestoration of civil order - in the wake of a previous cometaryfracture and its chaotic aftermath. But this end was essentiallyrealized and it may well be now that western civilization requires anattitude to these events in future which is a good deal more subtlethan the official American approach currently allows.

There are new understandings of our environment, then, to be taken on board. Thusthe last millennium or so tells clearly enough of a Western Europeancivilization which eventually took over the New World but which wasalso oppressed by cosmic inputs considerably more than most of us havebeen given to believe.

It also tells of a civilization driven to such extremes bythese external pressures that the subordinate and more reliableelements of society could only seek their freedom by aimless uprisingwhile others with the means and some sense of purpose sought theirfreedom by escaping their environment.

Viewed negatively on the one hand, the cosmic inputs are anunbearable overpressure which society characteristically fails toresist and which has a roughly one in four human lifetime chance ofrecurring; viewed positively on the other hand, the same inputs are thecause of 'punctuational crises' which are also the principal opportunity for civilization to step out of its mold.

Each new search for civil order in the wake ofoppression and chaos has proved to be an added spur to civilization'sadvance and a likely paradigm shift.

Something of the right note here may be struck by Trevor-Roper(1987) when he tells us, albeit without any reference to an increasedfireball flux, how:

... in Germany, the ideas of Paracelsus were combined with [ ]metaphysical speculations: how there too a new era of enlightenment wasexpected to follow the return of a chemical prophet, 'Elias Artista',who would make all things new; and how the beginnings of the ThirtyYears War were seen as the 'shakings' which would precede the fall ofAntichrist and, as it were, light the fuse for the great eschatologicalexplosion. That did not work out according to plan; but in 1640, when anew series of 'shakings' began in England, hope was rekindled. TheEnglish Puritan Revolution, which we see as a purely national struggle,appeared to many European Protestants as an event of internationalsignificance, the second stage of the Bohemian Revolution of 1618. Somessianic expectations were renewed and central European enthusiastslooked, and sometimes came, to an England which, they hoped, havingreclaimed its historic role, would realise the Bohemian promise ofenlightenment as the prelude to the millennium.

Trevor-Roper goes on to point out that many of the time were indeedresponding to the same intellectual challenge. For at one extreme ofthe Reformation-Counter Reformation debate we find an anticipatedmessianic return: that of the likes of 'Elias Artista', essentially thelate medieval rendering of neo-Platonism's cosmic demi-urge, for whichsuch as Bruno would go to the stake; whereas at the other extreme ofthe debate, we find a desire for permanence and stability: anestablishment set against any Pyrrhonist (catastrophist) perception anddetermined at all costs to preserve for Christendom its basic(Aristotelian) cosmic theme. It seems though that "none of themproduced a final answer. But in the convulsion of their time the oldcompromise was destroyed, or at least emptied of its real content, andall of them, out of its relics, incidentally contributed something tothe succeeding age..."

In other words, there is a perspective on the historicalprocess which now tells us that the Renaissance needed its Inquisitionto preserve the perceived cosmic order and suppress the omens which theastrological view of nature nevertheless allowed.

Likewise the English Enlightenment needed its officialridicule to counter the cometary threat which the scientific view ofnature essentially allowed.

But now, with space tentatively explored, thepublic has learned that neither the Inquisition nor official ridiculewill impede future cosmic inputs.

The US Congress no doubt will decide how these inputs will bechallenged - but if realism is to prevail, and ridicule no longerworks, the new understandings of our cosmic environment will imposetheir new discipline on society as well!

In short, society still has to come to termswith the seriousness and comparative urgency of the cosmic threat andto recognise the need for an enabling contract between mankind and itsleaders which guarantees both the discipline and the challenge.

Fig. 2. A broadsheet issued from Augsburg on the occasion of the 1521 comet, as illustrated in the upper right hand frame of the montage. Note the anticipated seismic effects due to cometary debris, as illustrated in the upper left hand frame, typical of the perceived nature of 'last times' and low-level multimegaton explosions. The lower frame is of particular interest in that it gives expression to the common general response on the part of ecclesiastical authorities and secular administrations to the activities of those who dispensed prognostication and the mitigation of fear in the presence of celestial signs (astrologers, soothsayers, witches etc.). The encitement of unrest in society through over-zealous attention to 'last times' was clearly a serious problem so far as our ancestors were concerned, one that remains to be tested in modern times!

If history is a guide, the necessity of preventative action will ofcourse be ignored! Thus the situation is by no means new and hasoccurred many times before (Cohn, 1957; 1993). Recent studies have probably given us a pretty good idea how societies respond in extreme circumstancesand, to encapsulate these, we can do worse than go back to thebeginnings of western civilization itself. For it is here that we findhow the Roman Empire became aware of and confronted the cosmic threatduring its fourth and fifth century decline, essentially realising thatneither Stoics nor Epicureans had any answer to the intense publicanxiety which then emerged.

Thus, it came about, so it now appears, that a whole subjugatedpeople extending from the Eastern Mediterranean to Western Europerather suddenly succumbed to the blandishments of a Christian community(Brown, 1971) which promulgated the notion that one could escape thetorment of "demons" by electing to "belong" to an everlasting (cosmic)community of "saints". By associating these demons and saints withmembers of the human population as well as with clashing celestialarmies and hence with an observed circulation in the sky (Section 3.5),it seems that this Christian notion had its basis in verifiable cosmicfacts which had been endorsed by neo-Platonists such as Proclus andAugustine.

The point here is that a basic classical view of the Universe,originating with the pre-Socratics and given its most perfectexpression in Plato's Timaeus, reached its zenith with theneo-Platonists. Plato and the neo-Platonists described how a divineagency, the demi-urge, had constructed the main features of the visibleheavens: a planetary system in the plane of the ecliptic which probablyincluded the Earth in orbit around the Sun and another divinecirculation inclined to the ecliptic which not only intersected thepath of the Earth but supposedly reached out beyond the sphere ofstars. It was this circulation apparently, with the characteristics ofelliptical motion and precessing nodes, which returned to the Earth atlong intervals with catastrophic consequences. However the morecultivated and sophisticated elements of Roman society were not atfirst prepared to go along with this expectation. Rather both secularand ecclesiastical opinion discounted the demi-urge and held to an(Aristotelian) perception of the environment which presupposed somedegree of permanence and stability in the cosmos at hand.

Before enduring the Dark Age however, the Roman Empire was to behorrified by the imprint of "deserted areas" which contemporary opinionclosely associated with the imminent arrival of world-end (EsmondeCleary, 1989). Such devastation now seems to have the character ofsuper-Tunguska events; and, indeed, one such putative event in England,as the particular country in question was to become, was subsequentlyattributed to "the fire of righteous vengeance".

While enlightened scholarship has for long been in the habit ofridiculing the implications of such phraseology, several historianshave recently gone out of their way to emphasise the essentially dramaticnature of this event and its consequences. These, realisticallyinterpreted, appear greatly to exceed those expected with a mereexploratory invasion by a boatload of (Anglo)Saxon brigands asenlightened scholarship would normally have it (e.g. Myres, 1986 cf.Clube, 1992).

In other words, the possibility of severe cosmic events is no longerin principle denied and it may therefore be hardly surprising thatideas put about by neo-Platonists during the fourth and fifth centuriesshould have been in the ascendancy.

During the sixth century Justinian period, indeed, the socialupheaval and environmental calamities appeared to be scaling newheights and it is not without significance that a firm administrationthen closed down the Platonist Academy in Athens and therebyeffectively created a subversive undercurrent of astronomical knowledgewhich was to remain at the heart of Christendom's intellectual discordfor at least another fifteen hundred years (e.g. Lindberg, 1992)!

Thus it was in the aftermath of catastrophe, during the latter halfof the Justinian administration, that (Byzantine) Christendom securelyembraced Aristotelian doctrine for the first time, to be followed acentury later along this track by (Muslim, non-Arab) Islam (e.g. Brown,1971). Subsequently, another five centuries were to pass beforeAristotelian doctrine was also embraced by Western European Christendomby which time the latter came to be seen as having experienced anintellectual dark age of some seven or eight centuries.

Now, as we acquire an improved understanding of the relevant cosmicfacts (Section 3), it seems that the crucial scientific advances laterengineered by Kepler, Bruno, Galileo and Newton provided us with thebasic framework which eventually led to the Space Age revelationsculminating with the split comet by Jove and which will in due coursemark the astronomical notions of the neo-Platonists as ones whichshould never have been set aside!

3. EVOLUTION, PUNCTUATIONAL CRISES AND THE THREAT TO CIVILIZATION

3.1. Punctuated Equilibrium

The idea that evolution on Earth proceeds at a uniform pace towardssome undefined state of perfection in the remote future has given wayin recent years to one involving successive states of "punctuatedequilibrium" (Gould and Eldredge, 1977). Thus, in keeping withevolution's supposedly progressive nature, it is assumed that both theenvironment and the distribution of living species remain in successiveuniformitarian states for characteristically long periods of time andthat these also begin and end with much briefer periods when both theenvironment and the distribution of species undergo very rapidupheaval.

There is an implicit assumption here, of course, that the upheavalsare then necessarily progressive whereas in practice the condition ofthe environment along with the distribution and character of species,treated broadly as a geophysical/biophysical cumgeochemical/biochemical state, is probably most simply perceived asexperiencing a catastrophic recession followed by a catastrophicadvance. An 'advance' as such does not then have any absolutesignificance but is merely said to be so on account of itsretrospective accord with the direction taken to reach the followingequilibrium state.

Under these circumstances, it is to be expected that we are dealingwith uniformitarian states which are broadly regressive rather thanprogressive - that is, tending towards some statistically average staterather than deviating from it - and punctuational states which broadlycomprise a recession forced by cometary input and an arguablydeterministic advance forced by the random disequilibrium so inflicted.

The significance of cometary inputs is that they allow bothbiophysical and biochemical effects i.e. cosmic insertions reachingdifferent levels in the atmosphere which are capable of generatingeither catastrophic explosions or catastrophic loading of theatmosphere with particulate material (dust) bearing biologically activechemicals. If this understanding is generally correct then itis clear that the Darwinian perspective on evolution, suggestive of anintrinsic directional quality in natural selection, is no longersupported and that we should look to the random yet (in principle)predictable cosmic inputs and their induced chaos as the fundamentalcontrolling factor determining the course of evolution.Natural selection, on this account, is but a counterbalancing processtending to preserve equilibrium after a disturbance and is essentiallymundane!

With the advances during recent years in our knowledge of theastronomical environment, there has been a tendency to suppose these'punctuations' might reasonably be associated with isolated 'impactcrises' due to encounters with single bodies in Earth-crossing orbits.While, as a matter of definition, it might be considered arguableexactly what level of crisis qualifies as a punctuation in theterrestrial record, one can perhaps assume, as a matter of principle,that only those impinging bodies capable of significantly influencingthe whole globe for a brief period should be considered.

It is on just such a basis apparently that single near-Earth objects(NEOs) greater than a kilometre or so in size have come to be the newfocus of attention so far as terrestrial evolution is concerned.Indeed, through this rather simplistic perception, recognizing alsothat the human species is a global phenomenon, the notion that km-plusNEOs are the most serious threat to civilization has recently gainedsome impetus (e.g. Chapman and Morrison, 1994).

Civilization however, is not something that we necessarily associatewith mankind as a whole; rather we envisage several different'civilizations' which occupy different parts of the globe at any onetime; and many 'civilizations' during the course of history which haveflowered and foundered (e.g. Spengler, 1932; Toynbee 1945).

Civilization, in fact, treated as a modest evolutionary aspect ofthe human species, not only appears to be associated with distinctethnographic and demographic qualities of mankind but tends to beregarded as a local rather than a global phenomenon; in which case, thetheory of punctuated equilibrium would seem to require that singleor multiple sub-km NEOs capable of depositing massive dust veils orinducing super-Tunguska events represent the commonest and hence mostlikely serious threat to an individual civilization.

At the same time, it may have to be admitted that the modern trendtowards the rapid 'globalization' of civilization and its otherqualities is perhaps rendering these characteristics more synonymouswith mankind as a whole than was formerly accepted. But howeverglobalized and/or superficial the evolutionary characteristics ofcivilization may be, it is clear that this more qualifiedunderstanding of punctuated equilibrium allows the possibility oflocalized evolution of a dominant strain in association with alocalized cosmic input such as a super-Tunguska event and of the globalextension of this dominant strain in due course. Such a turnof events is not excluded apparently by the present condition of thehuman species and its evolution from a single African location duringthe past million years or so.

It follows from considerations such as these that the evolution ofcivilization may be no more than a simple extension of the evolution ofbiological species. Thus we are accustomed to the idea of punctuatedequilibrium in biological evolution reflecting isolated encounters withthe single km-plus (meteoritic) asteroids which have undergone a priorseries of orbital deflections since leaving the asteroid belt. But weare less familiar perhaps with the idea of 'punctuational crises'affecting biological evolution and the advance of civilization, thesebeing due to the more sustained bombardments by fragmentation debriswhen active, dormant or dead comets which have deviated from the mostlikely source of comets (the Oort cloud, say) undergo significantsplitting in Earth-crossing orbits. Such orbital debris encounteringthe Earth's atmosphere is evidently capable of introducing bothhigh-level dust and low-level explosions, depending on its mass andcohesive strength, and it follows that punctuational crises arecomprised of global coolings and super-Tunguska events together with agenerally enhanced fireball flux.

Taken as a whole and in conjunction with a given planetary target(e.g. Jupiter, Earth etc.), the response function to the bombardmentsis inevitably complex. Nevertheless, we can broadly expect that thestrength of a punctuational crisis will vary as the progenitor cometmass, the inverse (velocity) dispersion of its debris and the inverse(time) delay since fragmentation. In which case the encounter betweenComet Shoemaker-Levy 9 (P/SL-9) and Jupiter may be taken asrepresenting an extreme punctuational crisis where the dispersion anddelay were small.

An extreme punctuational crisis affecting our planet and involvingmultiple comet fragments may also be envisaged for such evolutionaryevents as the mass extinction of species, for example the KT event 65Myr ago. Such rare events however are at one end of the evolutionaryscale: at the other end of the scale, we deal with the lesser but morefrequent crises affecting the Earth which have disturbed civilizationseveral times during recent millennia - these may have had smallerinverse dispersions and smaller inverse delays but are no lessimportant for that!

Indeed, such crises can now be regarded as the smallest units of ouroverall catastrophic experience; and to place them in perspective, weneed to consider the catastrophic record as a whole. This leads us torecognise the relatively sudden flowering and foundering ofcivilizations during interglacials as the principal signatures ofpunctuational crises that arise as the corresponding debris of a giantcomet in a short-period, Earth-crossing orbit passes through the finalstages (splittings) of its evolution and decline.

Thus we envisage a situation where the particular mass distributionof comets settling in Earth-crossing orbits includes occasional verymassive candidates up to a few hundred kilometres in size for it is theevolution of these very massive comets which seems to be dominant inthe terrestrial record. For example, the contemporary millennia can nowbe seen in the context of successive myriads of years (104 - 105yr) in which the global coolings either persist (a glacial period underthe control of a disintegrating giant comet) or remain largely inabeyance (an interglacial period under the control of a largelydispersed giant comet).

The interwoven glacial-interglacial structure which is thenimprinted from time to time on the terrestrial record and correspondsto ice ages some - 106 - 108 yr in duration isthen readily enough understood in terms of Oort cloud perturbationswhich characteristically last for such periods of time and of aresulting overall flux of giant comets settling in short-period,Earth-crossing orbits which is apparently not so very different fromthat currently observed (Bailey et al., 1994).

The evidence, in other words, seems toindicate that it is the cometary flux which dominates the generalcourse of biological evolution, the general course of the globalclimate and the general course of the civilization to which we belong.

Such pre-eminence in terrestrial affairs accorded to cometsremains, of course, a very uncomfortable proposition for much oftwentieth century civilization and science.

3.2. Cumulative record of catastrophes

Our knowledge of the impactor flux reflecting the general state ofthe inner Solar System environment is largely based on the cumulativecounts of impact craters formed on lunar mares since the end of theheavy bombardment phase. As a result, the diameter-flux relationshipfor the largest impactors arriving at the Earth is commonly representedby a simple uniformitarian power law:

Φ(D) = k D -α, 1 <= D <= 102.5 km

Continuity considerations require that this relationship isapplicable to the potential impactors in Earth-crossing orbits whichare currently observed. Amongst these we must include theEarth-crossers having intermediate and long period orbits which reachout beyond Jupiter towards the Oort cloud. However, their particulardirect influence, in comparison with that of the Earth-crossers insub-Jovian space, which principally derive from short-periodaster­oidal (mainbelt) and short-period cometary (Jupiter family)reservoirs, is so small that they can reasonably be neglected for thepurposes of the present discussion.

It follows that the asteroidal and cometary bodies of interest inEarth-crossing orbits, comprising mostly their sub-asteroidal andsub-cometary fragmentation products which encounter the Earth(mete­orites and meteoroids, respectively), are essentially thosesurviving in two sub-Jovian orbital regimes. These have 'dynamicallifetimes' of ~ 108 yr and ~ 106 yr,respectively, depending on the eccentricity of their progenitorinjection orbits - below and above 0.5, say. Thus, so far as theseshort-period reservoirs dominating the terrestrial influx areconcerned, it is basically or­bital eccentricity which determines thelikelihood of a grazing encounter with a major celestial body such aswould tend to remove these smaller bodies from inner Solar Systemspace, and it is now recognized that the terrestrial planets are mostlikely to play this role when e < 0.5 (Wetherill, 1988; 1991) while the Sun and Jupiter are most likely to play this role when e > 0.5 (Froeschle et al., 1995).

Transitions between these orbital regimes are not of courseexcluded, so their unique cat­egorization in terms of asteroids andcomets, respectively, cannot be absolutely relied upon. Nevertheless itis broadly the case that meteorites and meteoroids have differing(top-heavy) mass distributions and fragmentation spectra as well asdiffering physical and dynamical life­times with the result thatcometary-meteoroidal impactors, unlike their asteroidal-meteoriticcounterparts, cannot be expected to achieve a fully relaxed spatialdistribution with respect to solar ecliptic longitude and latitude. Inother words, the minor body flux of cometary origin normally takes aperiod of time to become fully sporadic which is significantly inexcess of its physical survival time. The result, as a consequence ofhierarchical disintegration, is that the sporadic distribution is onlypresent at higher (D > 1 km) and lower (D < 10-3km) mass lev­els while the uniformitarian law undergoes an observed steepening in the intermediate range, such that

Φ(D) = k D -β, 10 -3 <= D <= 1 km

where β > α (Shoemaker, 1983). The relationships (1) and (2) arebased on the lunar cratering record but we can also determine thediameter-flux relationship for smaller impactors currently arriving atthe Earth, as derived from the bodies in space which are observedeither in situ or penetrating the atmosphere (Rabinowitz et at, 1993;Ceplecha, 1992; Tagliaferri et al., 1994), whence it turns out that

Φ(D) = 10 - 100 X Φ(D), D<= 10-2 km

This may evidently be understood as a temporary condition, also inaccordance with the observational steepening, and has for some whilebeen attributed, as we have seen, to a still disintegrating, very largecomet (Kresak, 1981) of the kind now believed to be present in theinner Solar System from time to time (Δ t ~ 105yr; Bailey et al., 1994).

The steepening thus straightforwardly implies that the commonest'evolutionary events' on Earth relating to the low mass end of theSolar System minor body population (i.e. 10-1 < D < 1 km) are due to correlated encounters with the hierarchically disintegrated products of the debris from successive giant comets.

The appeal to a contemporary giant comet does of course represent a general departure from uniformitarianism on timescales 10E4 - 10E6yr, the typical interval between giant comets settling in sub-Jovianspace. The cumulative record of catastrophes thus leaves open thequestion whether there are additional modulations of the terrestrialrecord on timescales < and > 10E4 - 10E6 yr which would also be indicative of a predominantly cometary influence on terrestrial evolution.

3.3. Punctuational crises

To many investigators, the idea that isolated impact crises risingabove some global threshold are the only astronomical influence we needconsider when dealing with evolutionary processes in geology andbiology is simply not compatible with the evident complexity of theterrestrial record (Hallam, 1989). Thus it is widelyrecognized that long-term climatic and other factors must also beinvolved and it has been known for seventy years that the terrestrialrecord is marked by periodic and stochastic modulations on timescalesbetween 106 and 109 yr indicative of a Galactic driving force(e.g. Holmes, 1927). Indeed it is for these reasons that manyinvestigators in recent years have given greater credence to a cometary(Oort cloud) rather than a (Mainbelt) asteroidal source of'punctuational crises' (see Section 3.4).

The role model for punctuations then is not the ostensiblynarrow epoch associated with a random (km-plus) asteroid; rather it isthe considerably broader epoch associated with the relativelyshort-lived, orbitally correlated, disintegration products of anot-so-random (km-plus) comet.

There are several points to be made here. First, these considerably broader epochs may be characterized by one or more global coolings and/or super-Tunguska events occurring as a prelude to or in association with an enhanced fireball flux:events of this kind are to be expected as a consequence of high-leveldust insertions and low-level multimegaton explosions such as may beproduced, depending on their cohesive strength, by sub-cometary massesof about 0.1-1 km in size. Secondly, both the cometary mass function(which is top-heavy) and the tendency of comets to undergo rapiddisintegration determine that a high degree of coherence may be presentin the incidence of sub-km and km-plus comets on Earth at any one time.

Cometary material in general is capable of being active, dormant ordead and for inner Solar System material of this kind whosedistribution does not evolve and which has broadly unchanging orbitaland constitutional characteristics, it would certainly be expected thatthe frequency of punctuational crises (as now defined) at any epochwould also be broadly un­changing and reflective of the integrated"minor body" mass "in residence".

With a variable mass content however, such as arises with thetop-heavy mass distribution of comets settling randomly in inner SolarSystem space, the pattern of punctuational crises may be expected totake on the general character of a glacial-interglacial with bothperiodic and random groups of events on timescales < 105 - 106 yr reflecting the orbital and fragmentation history of a particular giant comet (e.g. Asher and Clube, 1993).

In other words, as a consequence of the cometary mass distribution,we envisage punctuational crises which are themselves hierarchi­callynested in the overall manner of glacial-interglacials, each lasting ineffect for the duration of ~ 104-10 orbits inaccordance with the size of the parent comet within the nestedhierar­chy i.e. from a few hundred to a few kilometres in size. It isthus in the general nature of the intermittently top-heavy populationof comets deposited in inner Solar System space that our planet isbound to experience glacials and interglacials, the latter beingthemselves interspersed with global coolings of shorter duration whichare in association with super-Tunguska events and sustainedenhancements of the fireball flux. Several facts then come together toinform us as to the likely nature of the current environment:

a)the disintegration products of comets(meteoroids) currently incident upon the Earth outweigh thedisintegration products of asteroids (meteorites) by one or two ordersof magnitude (e.g. Tagliaferri et al., loc cit)

c) the current interglacial follows on a recentglacial at ~ 20,000 ± 10,000 BP broadly suggestive of a recentlydisintegrated, very large comet and is itself inter­spersed withsustained enhancements of the fireball flux known on several occa­sionsto be correlated with severe global coolings (Asher and Clube, 1993;Clube, 1994; Baillie, 1994).

The evidence indeed points to the contemporary environment havingbeen dominated by an evolved giant comet and it is clear from thedynamical behaviour of other such bodies like Chiron further out in theSolar System (Bailey et al., 1994) that these extended inputs arecurrently recurring at random intervals ~ 10E5 yr. We may conclude thatit is the cometary punctuational crises which are dominant ontimescales < 10E6 yr.

3.4. The Holmes cycle

Unfortunately the cratering record is not yet well enough resolvedto describe with certainty any of its possible modulations ontimescales ~ 10E6 ~ 10E9 yr (Grieve, 1989). Nevertheless to the extentthat geological and biological signatures may be understood as proxy-signatures for punctuational crises,there is good evidence for a late Phanerozoic cycle of 26.3 Myr(Rampino and Caldeira, 1992) broadly confirming previous determinationsbased on the extinction cycle alone (Raup and Sepkoski, 1984 cf.Holmes, 1927). It also appears that the most recent maximum phase ofthis cycle coincides with a mid-Miocene peak ~13-14 Myr BP from whichthe early Pleistocene peak ~ 2 Myr BP introducing the Sun's latestGalactic plane passage is clearly distinguished.

On the assumption that geomagnetic reversal events in particularprovide a reasonably undistorted record of the major glacials due tolarge (inner Solar System) comets, the 26.3 Myr cycle is rather clearlyinterleaved with another cycle of the same period but lower amplitude;the two together being then uniquely associated with variations of thecontinuous and stochastic components of the Galactic 'dark matter' gravitational fieldacting upon the Oort cometary cloud, expected as a consequence of theSun's vertical oscillation about the Galactic plane (Clube and Napier,1996 cf. Matese et al., 1995). Quite apart from the not- unimportantimplications for dark matter and its nature, these cycles are in factstrong prima facie evidence of a very persistent influence onterrestrial affairs due to very large comets originating from the Oortcloud and we may conclude that cometary punctuational crises aredominant on timescales > as well as < 10E6 yr.

It is perhaps an interesting aside on the theory of punctuationalcrises that the latest two peaks of the compound Holmes cycle,correlating with two broad spasms of increased terres­trial activity,seem, respectively, to be associated with the first appearance ofhominids and with the eventual emergence of homo sapiens while theparticular activity that goes with the latest, very large, comet seemsremarkably well correlated with mankind's bare survival under stringentcircumstances at the end of the Pleistocene during a global climaticrecession (i.e. the most recent glacial at ~ 20,000±-10,000 BP) and thesubsequent rise of civilization dur­ing the Holocene. Civilizationin other words is merely the latest random facet of a continuinggalacto-terrestrial interaction expressed through the action of cometson the resident gene pool!

3.5. Spenglerian model of civilization

To recapitulate then: by studying the longer term cycles in theterrestrial record and some of the details in civilization's advance,we have now come to recognize the fundamental role of the Galaxy andcomets in terrestrial affairs. This role inevitably causes us to giveparticular attention to very large variations in the impact catastropherate. Indeed we can now recognize a broad category of evolutionaryevents described here as punctuational crises.

Punctuational crises can have an elaborate structure in practice butare no different, in principle, from the recent P/SL-9 encounter withJupiter. Thus the differences in general are merely those that arisedue to the differences in the target, the fragmentation agency and thedegree of orbital correlation.

So far as civilization is concerned, the aspect of thematter which gives punctua­tional crises their special distinction overisolated impact crises is their capacity for inducing socialdestabilization as a result of fragmentation and the perceivedstatistical inevitability of encounters with the Earth.

In the case of P/SL-9, since another planetary target was involved,mankind was able to take a detached view of the subsequent proceedings.In the case of an Earth encounter however, since the enhanced fireball flux is indicative of its more massive cor­relates,the view can never be detached. Such enhancements have in fact occurredfrequently in the past - ostensibly in association with the Tauridstream (Clube, 1994: see also Fig. 1) - and the next occurrence, as wehave seen, has a roughly one in four human lifetime chance.

Historically, inasmuch as these enhancements have frequentlybeen interpreted as indicating the imminence of 'last times',predisposing even the most advanced societies to break up and losecontrol, the corrective response has usually depended on thedisposition of society as it experienced punctuational crisis.

A study of past civilizations appears to indicate differing re­sponses dependingon whether society is subject to theocratic or secular control, thecrucial factor being the ability of the administration to maintainbasic freedoms whilst avoiding any descent into social chaos.

The situation is not satisfactory for it seems that theocraticstates will tend to censor any perceived deviation from the perceivedcelestial norm (whatever form this takes) while secular states willmerely seek to trivialize any threat posed by comets.

As we have already noted, neither censorship nor trivialization is likely to be effective in futureand it is not clear therefore that civilization is currently wellplaced to handle the next punctuational crisis. Indeed, any benefitaccruing to civilization through the uncritical endorsement of theSpaceguard programme (Chapman and Morrison, 1994) does little atpresent to alleviate the pressures due to the next punctuational crisis.

Ultimately, there is a problem here because we still belong to aperiod of human history in which the Darwinian or progressive view ofour past is so securely entrenched that we set aside contemporary andnear-contemporary proponents of any alternative view. There is no lackof concern of course as to the fate of civilization but academe stillrequires a supposedly uniformitarian terrestrial environment and asupposedly innate tendency on the part of the human species to evolvethrough natural selection towards some perfectly civilized state. Itseems in fact that the currently adopted scientific paradigm requiresus to take a severely anthropocentric view of the environment,virtually guaranteeing catastrophes will not occur.

Insofar as we pay any respect to the environment, we are encouragedto believe that mankind has it essentially under control. That is, weassume as a matter of principle that the environment can be preservedin a uniformitarian state. Accordingly we no longer pay much attentionto any teleological or eschatological view of history (Butterfield,1981; Bultmann, 1957) and have very little patience with historianssuch as Spengler (1932) or Toynbee (1945) who have seen in civilizationa necessarily ephemeral characteristic of the human species. The formerindeed, in his once renowned The Decline of the West, sawonly a tendency for the various cultures and their correspondingcivilizations to stand alone in space and time in a demonstrablyself-contained way. This was not to propose that the principalparadigms of a culture are not part of a longer term evolutionary trendbut to indicate that the paradigms which prevail across an interfacebetween successive cultures in time are characterized by a process ofrandom selection and a degree of rapid remoulding. Each suchculture-civilization so pre-formed did admittedly evolve but always ina repeated and characteristic manner which depended not somuch on the environment or the state of technology but on an innercombination of perceptions borne and successfully conveyed tosucceeding generations by a dominant founding group. Thusthere would be a frenzied 'spring' and a staid 'autumn', periods ofgrowing dominance and settled equilibrium, respectively, but alwayssuch civilizations would begin and end with periods of trauma whichmarked them off in time. Spengler described these periods of trauma as"psuedomorphic" rather than "punctuational", seeming to implynevertheless some kind of mainspring which he described as "cosmic".The nature of the cosmic mainspring has not been evaluated, as ithappens, but the model was applied to world history, as it was known,with some evident success - albeit with implications which, whilst theywere not accepted into the mainstream, have never been preciselyrefuted.

Foremost amongst these implications was the recognition of asignificant pseudomorphosis during the seventh century BC (cf Starr,1961) associated with the emergence of three major civilizations, thoseof China, India and the Mediterranean, culturally aligned with Taoism,Buddhism and Stoicism, respectively. Of particular significance to thelong term development of these civilizations, so Spengler inferred, wasthe emergence and decline during the subsequent millennium, of theso-called Magian culture centred on and around Babylon. This heevidently pictured as the main intellectual conduit through which thebasic knowledge of an underlying cosmic influence, as it was perceivedin earlier neighbouring civilizations such as the Persian, theMesopotamian, the Egyptian and the Aegean, came to be harmonized andperpetuated. Thus Spengler was able to describe how the domain ofChristendom became the principal bearer of an original, predominantlyMagian, culture which also underwent significant metamorphosis in thehands of the Greeks. But he also made it clear that this metamorphosiscreated inherent ambiguities since the modified culture experiencedsuccessive schisms at three determining councils (Nicea, Ephesus,Chalcedon) before spreading in its various doctrinal forms broadlyalong the Eurasian temperate zone.

The significance of the Magian culture, if Spengler iscorrect, lies then in its cosmic paradigm: the fact of alternativefundamental perceptions of the astronomical environment, both of whichcame to have very wide, almost global, acceptance by the majorcivilizations of the world.

Broadly speaking, what we are dealing with here is the (original)pre-Socratic or (later) neo-Platonic version of the Universe and thefact of an intervening unresolved schism which resulted in theAristotelian version of the Universe eventually being acceptedthroughout Christendom. We deal in effect with a pre-existing,essentially physical, perception of the astronomical environment whichtakes the Universe to be infinite in extent, both temporally andspatially; but, inasmuch as the trauma of pseudomorphoses have beenmoderated by the adoption of a more pragmatic philosophy, we also dealwith an imposed, essentially comfortable, perception of theastronomical environment which takes the Universe to be finite inextent, both temporally and spatially, and subject to external,benevolent control. It is the finite version apparently western civilization currently takes the lead in preserving.

It was Aristotle of course who reminded us of a mythical traditionof extreme antiquity in which the stars are gods and in which "thedivine embraces the whole of nature". But it was he also whodisapproved of the existence of any infinite object or any infiniteplurality of objects to explain the Universe, claiming instead that thefixed stars at the same distance from the Earth essentially marked thelimit of the world.

Plato, it will be recalled, likewise thought of stars and planetsalong with the sun and moon as relatively local features of theUniverse; but with the important difference in his case that theseobjects were all temporary products of the recent and evenon-going evolution of a former "cosmic egg". Thus Plato and hispredecessors quite clearly did not accept the Aristotelian limit andconsidered the Universe to be infinite. Indeed, the pre-Socratics andthe early atomists subscribed to the idea of innumerable worlds or"cosmic eggs" scattered throughout infinite space which passed into and out of existence.

The underlying idea was that of an infinite or 'boundless' Universewhose constituents therefore represented the unlimited 'stuff' of theUniverse. Such stuff was of an ungenerated and imperishable nature; itwas also in a state of eternal motion, being therefore classified asimmortal and divine. In addition though, the pre-Socratics werehylozoists in that they went beyond the mere atomistic conception ofdead matter in mechanical motion and the Cartesian dualism of matterand mind supposing that the primary stuff of the Universe carried insome form the essential characteristics of animate, conscious beings(e.g. Cornford, 1952). The soul-stuff of life on Earth, for example,was thus thought of as being in some kind of continuum connecting itwith the soul-stuff of a corresponding life-form in the visible,evolved heavens. The living world to which we belong, according to thepre-Socratics and neo­Platonists, was therefore a limited cosmic entityboth representing the evolved constituents of a particular cosmic eggand occupying a volume of finite extent in both space and time. It wasnecessarily part of the Universe but since the latter was of infiniteextent in both space and time, it was natural that the immediatelyvisible world was also perceived as the 'world-cavern'.

In effect, the 'world-cavern' was a cosmic setting for the livingcommunity, or species, to which we and our basic soul-stuff could beconsidered to belong. It was a cosmic setting which was also conceivedto possess a beginning and an end, both chaotic periods when therele­vant cosmic egg was considered to undergo deconstruction andreconstruction, respectively.

But whereas Plato's Universe gave us uniformity beyond the stars - aworld of cosmic eggs stretching from here to infinity and from now toeternity - together with an interaction beneath the stars betweenheaven and Earth, essentially permitting the basic astrologicalprinciple; we find that Aristotle's Universe, based on a similarframework of facts- gave us uniform (cir­cular) motion for the planetsbetween the stars and the Earth and thus an absence of any localinteraction between heaven and Earth within the world-cavern, essentially discarding the ba­sic astrological principle.

It is the discarded astrological principle ofcourse which removes the theoretical possibility of cosmic terrorafflicting civilization and which gives the Aristotelian Universe itsparticular charm so far as any pragmatic leadership is concerned.

One cannot be surprised therefore that ecclesiasticalauthorities and secular administrations, anxious to maintain some kindof stability in the face of cosmic stress, should be diverted by thecharms of a principle which merely 'saved appearances' and created theillusion of uniformitarian calm in the vicinity of our planet!Astronomers however do not have to be so diverted since the Universe,for them, is not a matter of wishful thinking!

Thus, broadly in line with the Timaeus, before mankind had achievedany kind of measure­ment which would indicate for certain the sizes anddistances of the planets, our 'world-cavern', was thought of as somehowdisplaying the typical characteristics of an evolving world amongst theplurality of worlds. The general appearance of the celestial sphereseemed to imply a stellar firmament outermost which contained withinits space two mutually inclined circulations of material derivedoriginally from the relevant cosmic egg. Plato is known to haveultimately regretted his initial opinion that the Earth lay at thefocus of these circulations. This suggests he may have favoured the'central hearth' or the 'Sun as the centre of the cavern while it wasthe Earth rather than heaven, of these mutually inclined structures,which comprised the visible bodies we now associate with the ecliptic.

Plato also considered that the original fashioning of thisconstruction was in the hands of the demi-urge, its apparent purposebeing to introduce an interaction between heaven and Earth which was toa large extent reflected in the meteoric phenomena which we observe.Thus it was fundamental to the whole perception that the heavenlycirculation returned to Earth with apocalyptic force at long intervalsof time; indeed, it was a specific and enduring characteristic of theMagian culture, having cosmic sig­nificance, that "something wasdescried in the far future, indefinitely and darkly still, but with aprofound certainty that it would come".

Eventually, as the perceived awesome nature of the forthcoming eventbecame even more intense, there was increased speculation as to thechar­acter of the world-cavern and its association with a succession ofdemi-urges (or 'craftsmen' - 'sons of God'). The latter supposedlyfashioned the successive ages of mankind, each new beginning beingmarked by the return of the everlasting fire and by the occurrence of apor­tentous cosmic birth, conceivably a cometary splitting and hence arecognizable 'messianic' sign (see Section 4.1).

In due course, the Magian culture would undergo transformationdur­ing the fourth and second centuries BC and then again during thefirst and third centuries AD before experiencing yet another profoundpseudomorphosis during the Dark Age period 400-­600 AD. By then, thebelief in the apocalypse had intensified to the extent that itpenetrated the doctrine of European Christendom where it was to remainfor at least another millen­nium undergoing yet further transformationand revival during yet further pseudomorphoses around 1100 AD, 1500 AD,1650 AD and 1790 AD, each time in association with enhance­ments of thefireball flux (Fig. 1).

At each of these epochs, the Platonist tradition is evidentlyrestored, most intensely perhaps during the Dark Age and theReformation, but each time only to be countered by revival of theAristotelian tradition. In fact, the fear of "last times" has neverentirely disappeared from western culture, notwithstanding Comet Bielaand the Darwinian Enlightenment, and perhaps there is now an increasedsuspicion, arising through the line of historical development whichSpengler perceived, that the modern influence of a Taurid progenitorand the ancient perception of a cosmic egg, both of which are believedto have fragmented and dispersed, have a great deal in common.

We might well suppose in fact that our Space Age findings inrelation to the Taurid/Encke stream are in close accordance with thepre-Socratic cosmic perception. In other words, the Space Age like atypical fireball flux enhancement, by arousing an intense awareness ofthe probable nature of our astronomical environment, can ultimately beseen as providing us with a cosmic perception equivalent to that of thePlatonist tradition; and it is natural that this should already havebeen countered (unsuccess­fully!) by an entrenched Aristotelianismopposed to the implications of the Taurid-Encke stream!

4. CELESTIAL INFLUENCE OF THE TAURID-ENCKE STREAM

The air we breathe can be remotely or locally sensed, e.g. throughour eyes and nose, respectively. Likewise, to the extent that it maycontinuously penetrate the Earth's atmosphere and produce condensationnuclei in sufficient numbers to constitute recognizable atmosphericfeatures e.g. noctilucent clouds, the material content of theinterplanetary environment is also capable in principle of beingremotely or locally sensed.

In most instances however, it appears that the air we breathe andthe material content of the interplanetary environment we are able todetect remain below the threshold of everyday experience. Thus theaction of the interplanetary environment tends to be substantiallyunmonitored and we can only build up our general picture of what isgoing on largely through a process of irregular sampling as and whenthe development of new technology unexpectedly provides us with a newcapacity to detect one of this environment's effects. The pace oftechnological progress has certainly advanced this processsignificantly during the Space Age but we cannot presume that thisperiod will necessarily have coincided with the interplanetaryenvironment's most dramatic effects.

4.1. Chinese astrological records

The basic perception now arrived at, as described in this article,is that of an extraterrestrial input which transfers to our planet fromthe sub-Jovian interplanetary environment and which in former times wasregarded as transferring from within the perceived 'world-cavern'.Included from within this region at the few percent level is theasteroidal-meteoritic material diverted from the main asteroid belt butthe dominant contribution by far from within this region, as we haveseen, is evidently the ecliptic-wide distribution ofcometary-meteoroidal material arriving at the Earth from the broadlyelliptical (i.e. helion/antihelion) circulation in sub-Jovian spacewhose main concentration intersects the Earth's orbit in late June andearly November (Stohl, 1986). The dominant component, being ofcomparatively recent origin, does indeed have a non-uniform-distribution in solar ecliptic longitude reflecting its continuedconcentration close to the orbit of the circulation's source; whence itfollows that this main concentration is also the likely mostsignificant target for intrusive hypervelocity impacts giving rise tointermittent disintegration events in sub-Jovian space.

The most prominent of these events resulting in significant dustsignatures, i.e. the so-called cometary trails, are then naturallyassociated with the largest bodies in inner Solar system space capableof rapidly undergoing hierarchical disintegration. Such bodies arelikely to be choked off and rendered inert by their dust-ladenenvironments; likewise they may be naturally associated with therelease of substantial daughter bodies, even as large as small comets,which separate only slowly from the parent source; and also withrelatively short-lived meteoroidal swarms in neighbouring orbits, whichmay retain their coherence long enough to be repeatedly penetrated byour planet.

The picture arrived at is evidently one which allows us to bringtogether such prominent in­terplanetary features as the well knownhelion/antihelion flux, the conspicuous Encke trail, the majormeteoroidal concentration which has been found near the core of thehelion/antihelion flux and the huge intermittent enhancements of themeteoroid flux known to us through Chi­nese astrological recordsmaintained during the two most recent millennia (cf. Fig. 1).

In fact, these records of fireballs are now rather firmly indicativeof the Taurid-Encke stream harbour­ing the bulk of the disintegratingmeteoroidal material in inner Solar System space and of successive major disintegration events every other century or so afflicting the Earth:the most recent of which probably gave rise to Comet P/Encke some shortinterval of time prior to its discovery in 1786 (e.g. Asher and Clube,1993).

Thus, while the sizes in general of prominent daughter bodies cannotbe readily predicted and while the absolute calibration of the Chineserecords is uncertain due to unknown variations in the monitoringprocess and the detection threshold, these records do neverthelessreliably suggest a stochastic Taurid source function which has givenrise to possible cometary apparitions and fireball fluxenhancements (x 10-­100) around AD 0-100, 400-600, 1040-1100,1400-1460, 1500-1540, 1640-1680, and 1760-­1800, the last ofthese active periods apparently bracketing the supposed formation epochof Comet P/Encke and the current Encke trail. It is perhaps surprisingto note on this account that Comet Encke could be merely the latest ina succession of demi-urges while the Encke trail harbours the principal(inert) remnant of the original giant comet which gave rise to theTaurid Complex (cf. Section 3.5)!

With regard to the observation of fireballs, it is worthnoting that a distinction can be drawn between the fluctuationsdetected since the 18th century and those detected prior to this period.Thus the former reflect as much the increased scientific activity inwhich we currently participate while the latter reflect a moderatelyuniform, slowly extending, observational regime in China and theOrient, particularly Japan and Korea.

For the duration of this regime, the astronomical interests of theOrient, like those of Europe, lay with portentous rather than withastrophysical phenomena, the maintenance of suitable records being to alarge extent professionally organised only in China (Schafer, loc cit).Given the presumed nature of this observational material, whatever theastrophysical reality giving rise to the recorded meteoroid flux andits correlates (e.g. high level dust insertions, super-Tunguskaevents), we can be confident that the phenomena, especially during theperiods of their dominance lasting for several decades at a time, wouldmost probably have been understood in both China and Europe as divinerevelations or rather fearsome exemplars of a natural (presumedastrological) process in which the cosmos necessarily interferes withterrestrial affairs.

Indeed, these enhancements of the meteoroid flux which, as we haveseen, are likely to be broadly associated with the most recent giantcomet to have settled in inner Solar System space, are of particularinterest in their European context since the periods of theirprincipal activity happen also to coincide with periods of pronouncedsocial and intellectual upheaval when it is clear that the normalascendancy of secular over fundamentalist modes of thought, affectingthe general view of the cosmos, experiences a sharp reverse.It is reasonable, in other words, to suppose these were the periodswhen cosmic agencies were expected to interfere in terrestrial affairs,when the inspiration due to the cosmos gave way to foreboding.

We note, for example, corresponding to these particular epochs: thetime of Christ, the Dark Age foundation of the Holy Roman Empire, theinitiation of the Crusades against Islam, the Great Schism, theReformation, the English Revolution and the American War ofIndependence allied with the French Revolution. The activities duringall these periods point to a much closer link between political,religious and cosmic affairs during the ancien regime thanhistorians normally countenance. In fact, the political consequences ofrevived fundamentalism and the renewed interest in demonic agenciesduring these periods, especially their destructive tendencies, oftenperceived as a millenarian threat (Cohn, 1957), no longer appear to bewithout an identified material cause of external origin.

The prevailing tendency nonetheless, since the 12th century, hasincreasingly been to regard demonic agencies as a heresy (Thomas,1971), not only distorting our view of the cosmos but raisingunwarranted doubts as to the reality of the likely eschatologicalassociations at these and earlier epochs.

4.2. Eschatology displaced

Eschatology is a relatively long-established if now somewhat obscurebranch of learning currently stranded somewhere in the hinterlandbetween history and theology where it remains comparatively untouchedby scientists and by historians of science. Its concern is with thedoctrine of so-called 'last times' or, more precisely, with theperceived occurrences which, as a matter of historical record, werethought of as bringing the known world to its final destruction.

The most recent authoritative account of eschatological theory byBultmann (1957) in his Gifford Lectures at Edinburgh indicates thatthis subject, which was of decisive importance for the long history ofthe West, developed in association with the ancient concept of aperiodicity in the course of world events. This idea originating withthe earliest known astronomical traditions based on the ancient NearEast, most probably involving a Zoroastrian tradition from Persia(Cohn, 1995), was later developed in Greek and Roman philosophy chieflyby the Stoic thinkers and is perhaps best known today through thereference in Plato's Timaeus to bodies from space which return at greatintervals to cause a serious conflagration on Earth: the general concept is indeed that of a universal catastrophe deriving from the cosmic Zeus from whom also radiated a new world.Thus the astrological literature countenances a periodically moribundworld-civilization in need of revival and restoration and the periodicemergence of a new star at the end of an aeon, or world-year, to mark the occasion.

Bultmann emphasises however that, in addition to this over-archingperception applicable to the known natural world, we must recognise inthe earliest historical narrative an account of normal human welfarecharacterised by occasional catastrophes, mostly cosmic, which aretypical acts of divine chastisement.

The point here is that the catastrophes of divine origin were once acommon enough perception to imply relatively frequent occurrence and itis against this background that ancient authors considered the moreserious effects of periodic universal catastrophes. Thus the Old andNew Testaments were fundamentally distinguished by the latter's addedanticipation of a forthcoming new aeon freed from Satan's(catastrophic) rule. The picture to be envisaged therefore was that ofa new 'world catastrophe' which would bring to an end both the lessercatastrophes and the sequence of past 'world catastrophes'. Inpractice, the precise start of the new aeon was subject to a good dealof chronological reckoning based on the apocalyptic scheme due toDaniel and there was growing agreement during the period of the 'Pax Romana', even amongst secular historians, that the new order would be introduced around 500 AD.

Historians of course are in dispute over the precise nature of theDark Age. The fact of major reverses in civilization in some parts ofEurope during the fifth and sixth centuries has to be set againstsurvival, often in reduced circumstances, in other parts. A decline inthe level of civilization in Britain, for example, which is said not tohave been restored for upward of twelve or thirteen centuries, isperhaps material enough evidence of the deprivation involved. Thus, inthe face of this kind of reality, whatever physical hardships wereendured, one can hardly be over-critical of survivors of a predictedworld-catastrophe who then appear somewhat casual about theshortcomings of a failed astronomical theory i.e. it can certainly beassumed that survivors would have recognized that the 'last times' didnot in fact arrive. It is perhaps but a short step therefore fromPlato's soul-stuff continuously emanating from the world-cavern to theperception of a versatile if somewhat magical 'divine providence'through which such effects as a partial conflagration might bejudiciously realized.

During a subsequent era, then when the possibility of a universalconflagration no longer appeared probable, one can perhaps understandthat a continuing cosmic struggle might be envisaged between the darkpowers of nature and unreasonableness on the one hand and divineprovidence on the other hand, the latter now losing its materialattributes and becoming primarily the source of free will andenlightened reason!

Thus, as Bultmann supposes, "the idea of the eschatologicalconsummation would later be interpreted as the victory of reason,regarded as the necessary end of the historical development". Indeed,by subsequently placing such an interpretation on the fifth centurywritings of Augustine, the Church can now be seen to move away from apurely naturalistic interpretation of the celestial influence. Howeverwe should not overlook the fact that the general period correspondingto the decline of the Roman Empire (400-600 AD) was in association withcircumstances which were widely seen as predictably marking a world-endof cosmic provenance (Barb, 1963).

In fact, such anomalies of the period as the desertion of majortracts of land and the forced migration of whole peoples(Esmonde-Cleary, 1989) point to an underlying cause of theDark Age which enveloped at least the whole of Europe and which couldwell have been be due to a succession of localized catastrophesinvolving super-Tunguska bodies as implied now by theformation epoch of Comet P/Encke and by the 1760-1800 and 400-600 ADenhancements of the fireball flux (Asher and Clube /oc cit). Thus acometary progenitor for the Taurid meteoroidal concentration is alsoimplied and it is the coincidence of the latter's orbital nodes withthe Earth's orbit around 400-600 AD which would now lead us to envisagea wholly material cause for the Dark Age.

The evident fact of a new aeon which was not freed fromSatan's rule can of course be eventually seen as a fairly pressingproblem for the leaders of the subsequent Holy Roman Empire andthere would have been a natural tendency for later scholars to deferthe arrival of 'last times'. Indeed it was to be a feature ofhistoriography, then in the future, that the apocalyptic tradition withits scheme of the four world empires of Daniel and the idea of aneschatological end to history were gradually reinstated as part of theprotestant tradition.

4.3. Paradigm shifts

In fact, the protestant tendency, which was most seriouslyaroused on the occasions of an enhanced fireball flux, was generallyintent on maintaining the apocalyptic tradition. The resultingdebate was of course a critical factor determining the pattern ofsocial upheaval and revolution throughout Europe until the end of theeighteenth century.

Indeed it is only since Hegel specifically pronounced against therole of "divine providence" in secular and philosophical affairs (e.g.Lewis, 1954) that the crises and catastrophes comprising the mainnational and world events have come to be seen as motivated bynon-cosmic disputes between oppressors and oppressed. In viewof the likelihood now of a straightforwardly natural (cosmic)explanation of the apocalyptic tradition, we have to face thepossibility that Hegel and his successors were mistaken as to the truenature of providence as well as to the prime cause of revolutions!

Amongst the twentieth century historians, both Spengler (1932) andToynbee (1945) have argued for the origin, growth and decay ofcivilizations, effectively in the tradition of escha­tological history,each new growth emerging from a preceding period of chaos so that themovement of history is brought about by an unpredictable factor,namely, the behaviour of a nation in a critical situation. Spenglerindeed perceived such situations as a quite natural extension ofbiological evolution as a whole. Thus he anticipated the theory ofpunctuated equilibrium with the following perceptive commentary:

"The picture that we possess of the history of the Earth's crust andof life is at present still dominated by the ideas which civilizedEnglish thought has developed, since the Age of Enlightenment, out ofthe English habit of life, [thus] Lye11's 'phlegmatic' theory of theformation of the geological strata, and Darwin's of the origin ofspecies, are actually but derivatives of the development of Englandherself. In place of the incalculable catastrophes and metamorphosessuch as von Buch and Cuvier admitted, they put a methodical evolutionover very long periods of time and recognize as causes onlyscientifically calculable and indeed mechanical utility-causes".

Rather "all that we see about us impels us to the conviction thatagain and again profound and very sudden changes take place in thebeing of plants and animals, changes which are of a cosmic kind andnowise restricted to the Earth's surface, which are beyond the ken ofhuman sense and under­standing in respect of causes, if not indeed inall respects. So, too, we observe that swift and deep changes assertthemselves in the history of the great Cultures, without assignablecauses, inferences or purposes of any kind".

To Spengler therefore, civilization is no more than the fullestdevelopment of a culture or a paradigmatic view whose principalcharacteristics are essentially dictated from the cosmically inducedchaos through which they emerge.

Accordingly, for example, we now see the fireball flux enhancementof 1640-1680 initiating the predictions of world end in England at thistime, based on the latest analyses of the Book of Daniel by scholarssuch as Alsted, Brightman and Mede (Trevor-Roper, 1987). Received intopopular currency alongside a breakdown in official censorship, these predictions were to precipitate social upheaval and intellectual chaos, as well as civil war and interregnumin the aftermath of which those affecting to make something of aprinciple out of pragmatic protes­tantism selected to discountprovidential fireballs (Sprat loc cit) and restore scientificcensor­ship. Thus was silenced the recently aroused Pyrrhonist(neo-Platonist) wing within the broad protestant tradition, tipping thebalance once again towards its more catholic (Aristotelian) wing. Thesewere the ambiguous conditions under which Newton was able to makepublic his science and yet keep private his eschatological speculations.

Likewise, while we may now see such understandings of the stellar,galactic and cosmological environments which have emerged during thenineteenth and twentieth centuries as enriching our understanding of anearlier, neo-Platonist perception of the boundless Universe, it seemsthat some of the perhaps less well known astronomical findings of theSpace Age now also provide us with an understanding of the Sun and itsplanetary and cometary environments which enriches our understanding ofthe Magian world-cavern!

To be precise, it now seems that the latter is neither altogetherimperishable nor is it altogether temporary. Rather the Sun, itsplanetary system and life on Earth are comparatively ancientconstructions from the boundless while it is the latest giant comet,also a product of the boundless, which we should now identify inparticular with the most recent evolution of the human species andupheavals on Earth. As such, this giant comet is merely the latest in acontinuing series, the overall picture being that of punctuationalcrises which extend over a wide range of intensities and whichtransform our understanding of biological and social history. Theoverall picture, furthermore, is one that necessarily provides divinerevelation and cosmic myth with a natural material content, nowessentially removing such entities from the realm of fantasy.

Indeed, it seems that the secular eschatological component oftheological debate throughout history can also no longer be denied. Inshort, there is inspiration and foreboding generated by a giant cometwhich has masqueraded as both a cosmic egg and a cosmic serpent. Thereis also a watershed in the modern perception of cometary facts markedby the fragmentation of Comet P/SL-9 which society and government wouldbe unwise to ignore.

5. ACKNOWLEDGEMENTS

A substantial section of this article is reproduced from two of theauthor's earlier papers, one of which was composed in collaborationwith Dr D. J. Asher. The author would like to thank the organisers ofthe 'Inspirations' conference for their patience during the preparationof this article. The author also wishes to acknowledge and express hisappreciation of the very material assistance, while this patience wasbeing exercised, provided by Dr. W. M. Napier and, through the goodoffices of Dr S. P. Worden and Dr. S. Nozette, by the USAF (EOARDSPC-93-4076).

Racine, Wisconsin - Three sophomore high school students at Racine'sPrairie School have discovered an asteroid, a feat that is probablyunprecedented.

Sophomores Connor Leipold, Tim Pastika and Kyle Simpson will namethe asteroid, now known as "2008 AZ28", in about four years, said theMinor Planet Center in Cambridge, Mass., the international body onsolar system objects which verified the discovery.

"It's extremely rare and I don't know if an asteroid has ever beendiscovered by high school students before," said their science teacher,Andrew Vanden Heuvel. "Ninety-nine percent are discovered byprofessional researchers."

The asteroid must be observed two nights in a row in order for it tobe considered an official "discovery," WISN.com quoted Heuvel.

"Asteroids are not easy to spot. They are very faint, about 10,000times fainter than the faintest thing you can see with your naked eyes.You need to know how to look for them," said Heuvel who estimates thatthe 2008 AZ28 asteroid takes approximately five years to orbit the sun.

Five undergraduate astronomy students at the University of Washington discovered 1,300 asteroid in 2005 and 2006.

Mason Woodhams described seeing a "green fireball track across the sky" at about 11.05pm last night (Tuesday).

"The head of the fireball was white-yellowy-orange with a brightgreen fire trail. The whole thing lasted no more than five seconds orso.

"It was quite low and slow in the sky between 15,000 and 20,000feet, quicker than an aeroplane but slower than a shooting star and ittraveled from east to west.

"This was obviously a meteor of some sort burning up, but the factthat it was so low in the sky and a brilliant green colour made this sounusual.

"I spoke to a science teacher this morning about this and he saidthat either copper or barium gives off a green flame when burnt. Asmost meteors are made from iron/nickel, I guess this makes this quite arare phenomenon."

Anyone else who spotted this mysterious fireball on Tuesday night can contact the Observer at observer@trbeckett.co.uk

Meteors from the Geminid Meteor Shower on Dec 14 could be seen all over the world, as seen here from Italy.

"At first I thought it was a satellite," Gross said. "But it wascoming too low and too fast. If it was a satellite coming down then itmust have landed somewhere and someone has to know about it."

Gross said he was out of bed to use the bathroom around 3 a.m. on Dec. 14, when he happened to look out the window and catch a view of the object - which he described as being twice the size of the moon - streak across the sky.

"I was looking north, at about a 30-degree angle, and saw it flyacross from west to east in an arching motion," he said. "It was sofast, just a second and it was out of sight."

Gross said the object had similar illumination to the moon, with a fuzzy outline and soundless.

But it's possible, according to an East Stroudsburg University astronomer, that the object could have a scientific explanation.

"The Geminid meteor shower had peak activity over Dec. 13 and 14,"said ESU professor David Buckley. "They were very visible this year andwould have been best viewed after midnight."

Gross' description of a bright white, fuzzy-outlined objecttraveling very fast matches known descriptions of the Geminid meteors.

The annual Geminid shower has a reputation for producing bright white meteors that leave few visible streaks.

"Something moving that fast would almost certainly be a meteor,"Buckley said. "And these meteors would have been visible all over theworld."

But Gross remains adamant that what he saw was much too large to be a meteor, at least one that no one else noticed.

"If it was a meteor it was a huge one," he said. "I wouldn't have thought much of it if it was a tiny thing."

Gross said his description might refresh the memories of anyone elsewho could have seen the object and not reported it. "It was a clearnight, no clouds," he said. "It's only a one-in-a-million chance that Isaw it. But if anyone else did, they'd remember."

Whatever it was, it had to have followed a high trajectory based on "how the splash spread," Danyluk said.

Astronomer Martin Beech said he wouldn't rule out the possibility of a falling meteorite, but the marks perplexed him.

To punch through ice nearly half a metre thick, the meteor wouldhave to be huge and would look like a bright burning ball with anassociated sonic boom, said Beech, who teaches astronomy at CampionCollege at the University of Regina.

"Usually, it's quite a distinctive rumbling sound and people tend to notice that sound," Beech told Sun Media from Regina.

But no one reported seeing or hearing anything unusual.

"The whole pond was covered in snow (on Friday) until this morning when we saw the strange marks in the pond," said Danyluk.

Beech said he wasn't aware of any reports of fireballs in the area.

He also noted that such an object wouldn't normally melt thick ice.

"If it wasn't a meteorite, what the heck was it?" asked the baffled astronomer.

Danyluk's neighbour, Aaron Soos, said the marks were puzzling and the phenomenon had residents talking all day.

Maybe it's a meteorite and maybe it isn't, but it's unlikely thesource of a mysterious hole at an Alberta golf course will bediscovered any time soon.

The octopus-shaped opening in the slushy ice of a golf course pondjust west of Edmonton has neighbouring homeowners abuzz with thepossibility a small piece of space could have plummeted to earth intheir very backyards.

But the mystery will likely stay submerged in the seven-metre-deeppond that provides water to irrigate the golf course, Glen Andersen, asuperintendent at The Links in Spruce Grove, said Monday.

"I think it's a safety issue now," said Mr. Andersen, who added hewouldn't want to inch across the thin ice in search of what may havefallen.

"We're not going to do that. We hope people don't come out here - we'd ask them to leave."

Residents first reported the hole Saturday, and reports of afireball in the sky two nights before have piqued the interest of many.

Mr. Andersen said while it's fun to ponder what may have fallen,those who work at the course are much more interested in golf. "It'skinda neat, interesting, but that's it."

Many objects can fall from the sky, but very few end up beingmeteorites, said University of Alberta professor Chris Herd, whocurates the province's meteorite collection.

Space debris such as pieces of satellites sometimes rains from thesky. The mystery object that caused the hole could even be a largepiece of frozen waste from an airplane, he said.

"The fact is that there could be a number of other possibilities forwhat punched a hole through the ice, and the fact that if there isanything, it's at the bottom of a pond, doesn't put it high on the listof priorities for investigating it, unfortunately."

While it's unusual with Canada's massive size for people to see afalling meteorite and actually be able to recover it, Herd says his labsees about 100 rocks a year that people think may be from space. Aboutone in 400 actually turns out to be.

A motorist who described seeing a big ball of fire in the skyThursday night may provide a key to the puzzle. Eric Whyte, who wasdriving on Highway 2 between St. Albert and Morinville around 10 p.m.,said he originally thought what he saw was a shooting star, but thebright-orange ball of fire with blazing tail didn't burn away.

Alan Hildebrand, a planetary scientist at the University of Calgaryand co-ordinator of the Canadian Fireball Reporting Centre, said thatdescription sounds like a falling meteorite.

He said he will review the data captured by an all-sky camera nearEdmonton to see if it captured a bright trace in the sky Thursday night.

"Certainly once we have enough information, we can tell thedifference between a natural object entering and man-made debris comingdown," he said.

Only between 60 and 70 individual meteorites have ever been found in Canada, according to Prof. Herd.

None of these has been recovered from a pond, he said. He explainedthe water could act quickly to destroy much of a meteorite's interest.

"You can actually have chemical reactions take place. You can havealteration pretty quickly. It degrades the original minerals that areinside, and it's harder to study for scientific reasons."

Prof. Herd added that under Canadian law, meteorites - which tend tobe heavy and can be worth a fair amount of money - belong to whomeverowns the land where they touch down.

The Geological Survey of Canada, which maintains the nationalcollection of meteorites, offers a minimum of $500 for the firstspecimen of any new Canadian meteorite.

Prof. Herd says he's happy to examine any potential meteorites thatare recovered, but it would be far too difficult to try to recoversomething that could end up being of no scientific interest.

"You'd need equipment to dive down into this pond," he said. "So ifsomebody entrepreneuring would want to do it, I'd be happy to look atwhat they might find, but I can't justify the expense to go looking."

The Arecibo Observatory in Arecibo, Puerto Rico will observe a newlydiscovered asteroid on Jan. 27-28, as the object called 2007 TU24passes within 1.4 lunar distances, or 334,000 miles, from Earth.

The asteroid, estimated at between 150 and 600 meters in diameter -about 500 feet to 1,900 feet, or the size of a football field, at 360feet, to the size of Chicago's 110-story Sears Tower, at 1,454 feet -was discovered by the University of Arizona's Catalina Sky Survey inOctober 2007. It poses no threat to Earth, but its near approach givesArecibo astronomers a golden opportunity to learn more aboutpotentially hazardous near-Earth objects.

"We don't yet know anything about this asteroid," said Mike Nolan,head of radar astronomy at the Puerto Rico observatory. Such objectspass near Earth with relative frequency, he said - approximately oneevery five years or so - but it's rare that astronomers have enoughadvance notice to plan for rigorous observing.

Using Arecibo's powerful radar, which is the most sensitive in theworld, researchers will gauge the object's size, observe its speed andmeasure its spin. Switching then to imaging mode, which will offerresolution to 7.5 meters - three times more precise than NASA'sGoldstone telescope, the only other radar telescope in the world - theresearchers hope to map the object's surface in detail. The Robert C.Byrd Green Bank Telescope, Green Bank, W.Va., will receive Arecibo'secho from the asteroid and transmit its data back to Arecibo.

TU2 is one of an estimated 7,000 near-Earth objects, its size or larger - most have never been closely studied.

"We have good images of a couple dozen objects like this, and forabout one in 10, we see something we've never seen before," said Nolan."We really haven't sampled the population enough to know what's outthere."

Arecibo's radar is vital for continuing to classify and understandsuch objects, said Cornell University assistant professor of astronomyJean-Luc Margot. "Arecibo does a fantastic job at getting images,discovering the shape, spin and reflection properties of such an object. . . all these things that are important to know."

The telescope will be trained on TU24 Jan. 27-28 and again Feb. 1-4. Goldstone's planetary radar observed it Jan. 23-24.

Contrary to expectations for a small icy body, much of the cometdust returned by the Stardust mission formed very close to the youngsun and was altered from the solar system's early materials.

When the Stardust mission returned to Earth with samples from thecomet Wild 2 in 2006, scientists knew the material would provide newclues about the formation of our solar system, but they didn't knowexactly how.

Combined long- and short-exposure images captured during the Stardust flyby of the comet Wild 2.

New research by scientists at Lawrence Livermore National Laboratoryand collaborators reveals that, in addition to containing material thatformed very close to the young sun, the dust from Wild 2 also ismissing ingredients that would be expected in comet dust. Surprisingly,the Wild 2 comet sample better resembles a meteorite from the asteroidbelt rather than an ancient, unaltered comet.

Comets are expected to contain large amounts of the most primitivematerial in the solar system, a treasure trove of stardust from otherstars and other ancient materials. But in the case of Wild 2, thatsimply is not the case.

By comparing the Stardust samples to cometary interplanetary dustparticles (CP IDPs), the team found that two silicate materialsnormally found in cometary IDPs, together with other primitivematerials including presolar stardust grains from other stars, have notbeen found in the abundances that might be expected in a Kuiper Beltcomet like Wild 2. The high-speed capture of the Stardust particles maybe partly responsible; but extra refractory components that formed inthe inner solar nebula within a few astronomical units of the sun,indicate that the Stardust material resembles chondritic meteoritesfrom the asteroid belt.

"The material is a lot less primitive and more altered thanmaterials we have gathered through high altitude capture in our ownstratosphere from a variety of comets," said LLNL's Hope Ishii, leadauthor of the research that appears in the Jan. 25 edition of thejournal, Science. "As a whole, the samples look more asteroidal thancometary."

Because of its tail formed by vaporizing ices, Wild 2 is, bydefinition, a comet. "It's a reminder that we can't make black andwhite distinctions between asteroids and comets," Ishii said. "There isa continuum between them."

The surprising findings contradict researchers' initial expectationsfor a comet that spent most of its life orbiting in the Kuiper Belt,beyond Neptune. In 1974, Wild 2 had a close encounter with Jupiter thatplaced it into its current orbit much closer to Earth.

One of the silicate material found in cometary IDPs are GEMS (glass embedded with metals and sulfides). Similar structures are found in Stardust impact tracks in aerogel but also in light gas gun shots of sulfide in aerogel at the Stardust impact speed.

Comets formed beyond the so-called frost line where water and othervolatiles existed as ices. Because of their setting far from the sun,they have been viewed as a virtual freezer, preserving the originalpreliminary ingredients of the solar system's formation 4.6 billionyears ago. The Stardust spacecraft traveled a total of seven years toreach Wild 2 and returned to Earth in January 2006 with a cargo of tinyparticles for scientist to analyze.

This is one of the first studies to closely compare Stardustparticles to CP IDPs. This class of IDPs is believed to contain themost primitive and unaltered fraction of the primordial material fromwhich our planets and other solar system objects formed. They arehighly enriched in isotopically anomalous organic and inorganic outersolar nebula materials inherited - through the presolar molecular cloud- from dust produced around other stars. IDPs are gathered in thestratosphere by high altitude airplanes (ER-2s and WB-57s) that aretypically more than 50 years old.

The Livermore team specifically searched for two silicate materialsin Stardust that are believed to be unique to cometary IDPs: amorphoussilicates known as GEMS (glass with embedded metal and sulfides); andsliver-like whiskers of the crystalline silicate enstatite (arock-forming mineral). Surprisingly, the team found only a singleenstatite whisker in the Stardust samples, and it had the wrongcrystallographic orientation - a form typical of terrestrial andasteroidal enstatite.

Objects similar to GEMS were found, but Ishii and the team showedthey were actually created during the high speed 6-kilometer per secondimpact of Wild 2 comet dust with the Stardust spacecraft's collector bymaking similar material in the laboratory.

In analyzing the Stardust material, Ishii's team used Livermore'sSuperSTEM (scanning transmission electron microscope). Ishii saidfuture analyses should focus on larger-grained materials, so-calledmicro-rocks, which suffered less alteration.

"The material found in primitive objects just wasn't there in thesamples," said John Bradley, another LLNL author. "I think this isscience in action. It's really exciting because it's just not what weexpected."

"Wild 2 doesn't look like what we thought all comets should looklike," Ishii said. "The Stardust mission was a real success becausewithout it, we would never have learned these things about our solarsystem. The sample return was vital for us to continue to unravel howour solar system formed and evolved."

In addition to Ishii and Bradley, other LLNL researchers include ZuRong Dai, Miaofang Chi and Nigel Browning. Other institutions involvedinclude UC Davis, the Natural History Museum of London, the Universityof Kent and the Netherlands Organization for Scientific Research (NWO).

Stardust is a part of NASA's series of Discovery missions and ismanaged by the Jet Propulsion Laboratory. Stardust launched in February1999 and set off on three giant loops around the sun. It begancollecting interstellar dust in 2000 and met Wild 2 in January 2004,when the spacecraft was slammed by thousands of comet particlesincluding some the size of BBs that could have compromised the mission.It is the first spacecraft to safely make it back to Earth withcometary dust particles in tow.

Founded in 1952, Lawrence Livermore National Laboratory is anational security laboratory, with a mission to ensure nationalsecurity and apply science and technology to the important issues ofour time. Lawrence Livermore National Laboratory is managed by LawrenceLivermore National Security, LLC for the U.S. Department of Energy'sNational Nuclear Security Administration.

Law enforcement agencies in our area are still trying to figure outwhat folks saw streaking low across the evening sky in East Montgomery.

Around 6:00 Thursday night , the phone started ringing at the Policeand Sheriff's Department. Callers thought it might have been anairplane falling from the sky. A swarm of rescue workers weredispatched to the area, but found nothing.

As of now, no one knows what it was. some in law enforcementspeculate it may have been a meteor. If we find anything out for surewe'll let you know.

A cellphone report received on Saturday 01.12.08. Domingo Moralesphoned Andrew Alvarez to make a report on sightings in the City ofPonce. Mr. Alvarez told him to phone me. Mr. Morales reported thefollowing:

1. His brother, a resident of Valle Alta, Ponce, told him that onFriday, January 4 2008 at 9:30 p.m,., his wife called him over to lookat a fireball over their house. Upon going outside , he saw an immenseball of red fire. The wife didn't see it approach, rather she saw itsuddenly appear and light up on the spot. It remained static for some20 minutes at an approximate altitude of 300 feet. It spent 20 minuteslighting on and off. The fireball finally diminished the intensity ofits color and began moving SW in a zig-zag pattern, going up and down.It had the apparent size of a baseball stadium floodlight.

2. On Saturday January 5, 2008 at 9:40 p.m., Domingo's brotherphoned again, this time to have Domingo climb onto the rooftop of hishouse to see if it was possible for him to see the fireball, as he (thebrother) was seeing it. Domingo lives in Los Caobos, but was unable tosee the object from his home. According to Domingo's brother, thefireball was over the same site, above his house and exhibiting thesame behavior.

At 10:40 p.m., the fireball reappeared. This time, Domingo's brothersaw it with nearly all of his neighbors. One of the neighbors was ableto photograph it with a cellphone. On this occasion, a twin-engineplane flew over the area 15 minutes after the fireball vanished. This[fireball] did not appear suddenly, it came in from [the town of]Adjuntas.

3. On Sunday, January 6, 2008, Domingo and his wife decided to visitDomingo's brother to see if the were lucky enough to see the fireball.Just as they got out of the car, at 9:30 p.m., they saw two white ballsof light to the SW which appeared to be joined. They looked like twoorbs to the naked eye, but binoculars revealed them to be two platelike objects joined together. These were higher up, at some 5000 feet.(Domingo is a pilot, and is therefore able to calculate altitude betterthan the average witness). In plain sight they looked like two joinedgolf balls. They separated a minute later -- one heading south andanother to the north.

Five minutes later, Domingo phone FURA [P.R. police aerialreconnaissance] and was told that they were going to send theirhelicopter for a look. Domingo never saw the helicopter engage in afly-over. Domingo recalls that while he observed the two orbs, a womanand her daughters stopped to ask him if they were seeing the fireballs.She added that the fireballs had been visible since November in thatlocation, becoming apparent between 9-10 p.m. and as early as 5 p.m.

4. No sightings were reported on Monday, January 7.

5. Today, Saturday, January 12, Domingo will return with a camera in an effort to take pictures of the objects.

On December 22, 2007, Wilmar and Frank were heading back towardBayamon from the city of Ponce. Upon reaching Av. Los Filtros around6:10 p.m., they watched the sunset and the arrival of twilight.Suddenly Wilma looked at the sky and saw what she at first thought wasa jet. She quickly realized this was not the case, and that it could bea shooting star, but dismissed the possibility as the object remainedin view and grew larger in size. She then thought it was a meteorite orsomething that had broken away and was falling toward the ground.That's when she asked Frank to look up, thinking that it was ameteorite or something similar. Frank told her it was a jet airplane.Wanda replied that those airplane left smoke in their wake, and thisone had light. She added that it wasn't a normal aircraft, as it wasflying forward and not the customary route followed by commercialplanes.

Frank agreed with this assessment, and continued driving as theykept their eyes on the object. When they passed the Military Academy,the object stopped. Judging by the way the light came down, [theobject] appeared cone-shaped. Suddenly, Wanda realized that anotherlight of the same size pulled up beside it and then over the object.Unlike the first one, Wanda did not see a descending shaft of lightfrom this craft. It only hung above the first one for some seconds.Then the cone-shaped object made a right turn (as if heading toward SanJuan) making an "L" turn. It did not turn like a commercial airlinerwould, rather in a perfect turn that startled the onlookers. Bothobjects moved in unison and the lights suddenly disappeared.

Yesterday the people of Santa Luc?a were surprised when a blackporous rock fell from the sky. Today the CASLEO (Astronomic Complex ElLeoncito) is analyzing the rock to determine if it is a meteorite ornot.

"It was like a fire ball that traversed the sky", several witnesses said yesterday.

Profesor Eloy Actis, director of the Observatory F?lix Aguilar, isbetween those who do not believe it is a meteorite because he claims"that it should weight more than 20 kg, when in reality it is only arock of only 2 Kg. It could be a volcanic rock, but due to the areawhere it fell, this will be highly unlikely."

Space scientists and government officialsare tracking two massive objects that are hurtling toward Earth, butonly one, a dead satellite the size of a bus, is expected to hitsomewhere on the globe.

Government officials said Saturday that a large U.S. spy satellitehas lost power and could hit Earth in late February or early March. Andan asteroid at least 500 feet long will make a rare close pass by Earthearly Tuesday, but scientists say there is no chance of an impact.

The satellite, which no longer can be controlled, could contain hazardous materials, and it is unknown where it might come down, said the government officials, who spoke on condition of anonymity because the information is classified as secret.

"Appropriate government agencies are monitoring the situation," saysGordon Johndroe, a spokesman for the National Security Council.

John Pike, director of the defense research group GlobalSecurity.org, estimates that the spacecraft weighs about 20,000 pounds and is the size of a small bus.Satellites have natural decay periods, and it's possible this one diedas long as a year ago and is just now getting ready to re-enter theatmosphere.

Jeffrey Richelson, a senior fellow at the National Security Archive,says the spacecraft probably is a photo-reconnaissance satellite. Thoseare used to gather information from space about adversarial governmentsand terror groups and to survey damage from hurricanes, fires and otherdisasters.

The closest approach of the asteroid, known as 2007 TU24, isexpected to be at 334,000 miles, or about 1½ times the distance ofEarth to the moon.

The nighttime encounter should be bright enough for medium-sizetelescopes to get a glimpse, says Don Yeomans, manager of theNear-Earth Object Program Office at NASA's Jet Propulsion Laboratory,which tracks potentially dangerous space rocks. The closest approach isexpected to be at 3:33 a.m. ET.

The asteroid TU24 is one of an estimated 7,000 so-called near-Earth objects.

An actual collision of a similar-size object with Earth occurs on average every 37,000 years.

Spotted in October by the NASA-funded Catalina Sky Survey in Arizona, TU24 is estimated to be 500 to 2,000 feet long.

The next time an asteroid this size will fly this close to Earth will be in 2027.

Contributing: Reuters

Comment: Lookat that! An asteroid is having a close encounter with the Earth and aspy satellite might hit the Earth, which no one is sure what kind ofmaterials it contains, yet harmful as reported. Interesting that SOTThas carried a few editorials, very recently, on the subject of threats to Earth from space debris:

This morning I was thumbing through a newly arrived book: Comet/Asteroid Impacts and Human Society,published by the eminent scientific publishing house, Springer, editedby Peter T. Bobrowsky and Hans Rickman. This book is a collection ofscientific papers presented at a workshop under the aegis of theInternational Council for Science. In the introduction, we read:

The International Council for Science recently recognized that thesocietal implications (social, cultural, political and economic) of acomet/asteroid impact on Earth warrants an immediate consideration byall countries in the world.

Wow! You think? You mean it's not just us here at SOTT (and a fewothers on the net) who are keeping track of the increasing number of Fireballs and Meteorites that suggest we are passing through rather dangerous areas of space, or that maybe Something Wicked This Way Comes?

Yes, it seems so. In the chapter entitled "Social Perspectives onComet/Asteroid Imact (CAI) Hazards: Technocratic Authority and theGeography of Social Vulnerability" we read:

Until quite recently, research into comet and asteroid hazards wasfocused on establishing the scale and scope of past impacts, credibleestimates of their recurrence, and models for physical impactscenarios. ... CAI hazards have moved well beyond the realm ofungrounded speculation and apocalyptic visions. The results representmore than just new findings. They revolutionize, or are about torevolutionize, some basic understandings about the Earth, its history,biological evolution and future. Although human life has had a tinyplace in the story so far, our longer term fate seems to be challengedby these forces and may be decided by them.

No kidding.

In a chapter entitled "Social Science and Near-Earth Objects: an Inventory of Issues", we read:

It would have been ridiculous, not too long ago, to admit openlythat you were thinking about asteroids and comets slamming into theEarth. Such events could mean the end of the world as we know it -TEOTWAWKI as millenialists call it - and that kind of talk is oftenridiculed. ...

Respectable people are pondering the issues. For example, S. PeteWorden, who is a Brigadier General in the US Air Force and DeputyDirector for Command and Control Headquarters at the Pentagon, has saidthat he believes "we should pay more attention to the 'Tunguska-class'objects - 100 meter or so objects which can strike up to several timesper century with the destructiveness of a nuclear weapon."

I located the General's commentsand they are now in the SOTT database. It seems that the above is notall the general said. In fact, he states quite unequivocally:

I can show people evidence of real strikes inflicting local and regional damage less than a century ago.Even more compelling are the frequent kiloton-level detonations ourearly warning satellites see in the earth's atmosphere. ... Within theUnited States space community there is a growing concern over "spacesituational awareness."

The general was writing back in 2000. "Less than a century ago."That would be after 1900. He said that there were "real strikesinflicting local and regional damage" since 1900?!

Did I miss something? Did all of us miss something?

Well, we'll come back to that soon enough. That's not what I wantedto talk about today. Today, I wanted to pick up where we left off lasttime, the end of the Hundred Years' War.

In the previous installments of this series of articles we havelooked at how the Black Death was probably a period of cometaryfragment bombardment leading to mass death on an unimaginable scale. Intoday's world, the equivalent would be the deaths of two, possiblythree billion people planet-wide and many animals as well. Justcontemplating what humanity would do with that many bodies to bedisposed of is daunting, not to mention considering how society wouldcontinue. The Black Death was no respecter of rank, either: the elitesdied in proportionate numbers to the masses of ordinary people. Thishas some interesting implications in terms of how the elites arelooking at the matter now, but again, that is something we will comeback to once we have a look at the evidence.

In our discussion of the Hundred Years' War, we learned that a greatcover-up was effected at the end of it all and this was mainly toreestablish the religious control of the masses because, of course,religious control has always been the right arm of princes andgovernments.

Inasmuch as it was popularly believed that the continued sterility of many years was caused by witches through the malice of the Devil, the whole country rose to exterminate the witches. This movement was promoted by many in office, who hoped wealth from the persecution.And so, from court to court throughout the towns and villages of allthe diocese, scurried special accusers, inquisitors, notaries, jurors,judges, constables, dragging to trial and torture human beings of bothsexes and burning them in great numbers. Scarcely any of those who wereaccused escaped punishment. Nor were there spared even the leading menin the city of Trier. For the Judge, with two Burgomasters, severalCouncilors and Associate Judges, canons of sundry collegiate churches,parish priests, rural deans, were swept away in this ruin. So far, atlength, did the madness of the furious populace and of the courts go inthis thirst for blood and booty that there was scarcely anybody who wasnot smirched by some suspicion of this crime.

Meanwhile notaries, copyists, and innkeepers grew rich.The executioner rode a blooded horse, like a noble of the court, andwent clad in gold and silver; his wife vied with noble dames in therichness of her array. The children of those convicted and punished were sent into exile; their goods were confiscated; plowman and vintner failed hence came sterility. Adirer pestilence or a more ruthless invader could hardly have ravagedthe territory of Trier than this inquisition and persecution withoutbounds: many were the reasons for doubting that all werereally guilty. This persecution lasted for several years; and some ofthose who presided over the administration of justice gloried in themultitude of the stakes, at each of which a human being had been givento the flames. At last, though the flames were still unsated, thepeople grew impoverished, rules were made and enforced restricting thefees and costs of examinations and examiners, and suddenly, as when inwar funds fail, the zeal of the persecutors died out. (Burr: Linden, Gesta Trevirorum (from his manuscript in the City Library of Trier.) Latin. Printed in Hontheim's Historia Trevirensis diplomatica (iii, p. 170, note) and in Wyttenbach and Muller's ed. of the Gesta Trevirorum See this LINK for many first hand accounts and details of the witch persecutions.)

Indeed, the question that led to the persecution of witches was areligious one: How could a world created by a watchful, benevolent, andengaged God be such a mess? Answering this question led to a growthindustry in persons and institutions dealing death and destruction. Wesee a lot of that going on in our world today: the "security industry"is booming in the mythical "War on Terror."

The Reformation divided Europe between Protestant regions and thoseloyal to the Pope, but Protestants took the crime of witchcraft no lessseriously--and arguably even more so--than Catholics. Germany, rifewith sectarian strife, saw Europe's greatest execution rates ofwitches--higher than those in the rest of the Continent combined. Witchhysteria swept France in 1571 after Trois-Echelles, a defendant accusedof witchcraft from the court of Charles IX, announced to the court thathe had over 100,000 fellow witches roaming the country. Judgesresponding to the ensuing panic by eliminating for those accused ofwitchcraft most of the protections that other defendants enjoyed. JeanBodin in his 1580 book, On the Demon-Mania of Sorcerers, opened thedoor to use of testimony by children against parents, entrapment, andinstruments of torture. (A Brief History of Witchcraft Persecutions before Salem)

The problem is, of course, that the primary targets in any suchpersecutions are those who talk about the calamities themselves andpoint out that the religious faiths are obvious failures and perhaps itmight be better to look at the world rationally and scientifically.Such individuals must be accused of being witches or "cults" andsilenced because they threaten the very foundation of WesternCivilization, Uniformitarianism and the Fascist control of humanity bysuch elements.

We know of what we speak first hand! Have a look at The Disappeared: SOTT.net and Google's conspicuous omissions and then have a look at this ongoing defamation undertaken by modern-day Witch Hunters: Laura Knight Jadczyk's Cassiopaea Cult.We wondered how long it would take the psy-ops folks to set up a 9-11framed attack on us. As I commented yesterday, we must scare thebe-jeezus out of the PTB or so much effort wouldn't be spent on tryingto shut us down, suppress us, and, failing that, defame us.

But, getting back to the subject at hand (if one is going to bedefamed, one might as well be defamed for telling the WHOLE truth!), inVictor Clube's narrative reportfunded by the USAF and Oxford, the next important period of cometarycalamity was the Thirty Years' War. Let's look at a short timeline justto orient ourselves.

1337 to 1453 - Hundred Years War

1347/48 - 1351 - Black Death (included in the time period of the Hundred Years' War)

1400 - Renaissance (begins as the Hundred Years War is ending)

1431- Joan of Arc burned at the stake for being a witch (included in the time period of the Hundred Years' War)

1484 - Pope Innocent VIII announced that satanistsin Germany were meeting with demons, casting spells that destroyedcrops, and aborting infants

1591 - King James authorizes the torture of suspected witches in Scotland

1600 - Renaissance ends "officially"

1606 - Shakespeare's "Macbeth" performed

1616 - Thirty Years War begins

1642 - Beginning of the English Civil War

1643 - The largest witch-hunt in French historyoccurred. For two years there were at least 650 arrests in Languedocalone. The same time was one of intense witch-hunting in England, asthe English civil war created an atmosphere of unrest that fueled thehunting, especially under Matthew Hopkins.

1648 - Thirty Years War ends

1651 - End of the English Civil War

1660 - Witch persecutions end - Europe saw between50,000 and 80,000 suspected witches executed. About 80% of those killedwere women. Execution rates varied greatly by country, from a high ofabout 26,000 in Germany to about 10,000 in France, 1,000 in England,and only four in Ireland. The lower death tolls in England and Irelandowe in part to better procedural safeguards in those countries fordefendants. (LINK)

1682 - England executes its last witch, TemperanceLloyd, a senile woman from Bideford. Lord Chief Justice Sir FrancisNorth, a passionate critic of witchcraft trials, investigated the Lloydcase and denounced it as a farce. Witch-hunting shifted from one sideof the Atlantic to the other, with the outbreak of hysteria in Salem in1692.

I'm not too sure why the Renaissance is said to end in 1600, looksto me more like it was probably the Thirty Years' War that ended it.But, never mind, that's the date range agreed on by most scholars.

The Thirty Years' War was fought between 1618 and 1648, principallyon the territory of today's Germany, and involved most of the majorEuropean powers. It began as an ostensible religious conflict betweenProtestants and Catholics and gradually developed into a general warinvolving much of Europe, related to the France-Habsburg rivalry forpre-eminence in Europe, which led later to direct war between Franceand Spain.

Notes to ponder: The Thirty Years' War also prettymuch spanned the reign of Louis XIII of France (1610-1643). Galileolived from 1564 to 1642. Many adherents of Catharism, fleeing a papalinquisition launched against their alleged heresies in France, hadmigrated into Germany and the Savoy. This may have been at the root ofthe initial religious conflict. In fact, Catharism may have fed theProtestant Reformation.

The Thirty Years' War was one which utilized mercenary armies to agreat extent, and these hired killers were said to have devastatedentire regions leaving the inhabitants to suffer widespread famine anddisease which decimated the population. This affected primarily theGerman states and, to a lesser extent, the Low Countries and Italy. Atthe same time, it bankrupted many of the governmental powers involved.Sounds a lot like what is happening today, doesn't it?

The English Civil War, which began after the Thirty Years War hadbeen going on for about 25 years (and was running out of steam andpeople), consisted of a series of armed conflicts and politicalmachinations that took place between Parliamentarians (known asRoundheads) and Royalists (known as Cavaliers).

The question is, do we find any mentions of comets or other strangeastronomical phenomena during this period of time? As it happens, we do.

David Herlicius published in 1619 a discourse on a comet that hadappeared shortly before, in 1618, and enumerated the calamities thatthis comet, and comets in general, bring with them or presage:

Desiccation of the crops and barrenness, pestilence, great stormywinds, great inundations, shipwrecks, defeat of armies or destructionof kingdoms . . . decease of great potentates and scholars, schisms andrifts in religion, etc. The portents of comets are threefold - in partnatural, in part political, and in part theological. [William Whiston and the Deluge]

The seventeenth-century was witness to numerous comet sightings,including those of 1618, 1664, 1665, and 1677. Inquiries into thesecomets produced a noteworthy number of scientific texts includingSamuel Danforth's An Astronomical Description of the Late Comet (1665), John Gadbury's treatise De Cometis (1665), and Robert Hooke's 1678 report to the Royal Society, Cometa. These accountscomplemented the earlier work of Brahe and Kepler and helped to expandthe emerging technical understanding of this particular cosmicphenomenon.

Regarding Kepler: His observations on the three comets of 1618 were published in De Cometis, contemporaneously with the Harmonice Mundi (Augsburg, 1619).

My search for direct source material giving evidence of unusualevents from this time has been rather frustrating. I have found thatthe only people reading the original documents are scholars whogenerally refer to the descriptions of the time as being hyperbole, ormore or less "religious" metaphor, so it is frustrating to find thatthese actual passages are quoted in the original language - generallyGerman. Not to be thwarted, I sent the material off to a German friendof SOTT and he quickly returned a translation.

In the journal, German Life and Letters 54:2, GeoffreyMortimer published an article entitled "Style and Fictionalisation inEyewitness Personal Accounts of the Thirty Years War". He writes:

Eyewitness personal accounts of the Thirty Years War are of interestnot only for their overt content, but as examples of how the process ofwriting itself can shape both the resultant text and the meaningderivable from it by the reader. Techniques adopted, probablyunconsciously, by writers seeking to give force and point to theirnarratives, here collectively termed 'fictionalisation', add towell-known problems of eyewitness testimony to affect the historicalevaluation of such sources.

We are going to see that, apparently, Mr. Mortimer hasn't beenreading the work of Victor Clube! He goes on for some pages explainingto us that the people who wrote these accounts were mostly simpleindividuals who had no literary pretensions, and the works themselveswere things like diaries and records intended to be passed down infamilies. One item that he says was written to "create the desiredimpression, possibly at the expense of strict representationalaccuracy" is the following:

Due to war, pestilence, price rise and famine, our people arereduced to such an extent, that it will be difficult for ourdescendants to believe it.

Now, one has to keep in mind the meaning of the word "pestilence" aswe discussed already in a previous section. Jon Arrizabalaga, in hisarticle included in Practical Medicine from Salerno to the Black Death, discusses the etiology of this word and how it was understood by the peoples of the time. He writes:

The emphasis placed on celestial causes of the 'pestilence' by thedifferent physicians studied here varied quite widely. ... In 1340Augustine of Trent, a friar eremite of St. Augustine, justified havingwritten a medical and astrological work on a 'pestilence of diseases'happening everywhere in Italy, because of physicians' ignorance aboutthe roots of diseases; this fact was considered by him 'a pestiferousmistake involving many physicians', and he blamed it on their 'ignorance of astronomy'. ...

Works from other geographical areas assigned a more relevant role to celestial causes in the genesis of the 'pestilence.' ...

Jacme d'Agramaont ...said nothing concerning the term epidemia, but he extensively developed what he meant by pestilencia.He gave this latter term a very peculiar etymology, in accordance witha from of knowledge established by Isidore of Seville (570-636) in his Etymologiae,which came to be widely accepted throughout Europe during the MiddleAges. He split the term pestilencia up into three syllables, eachhaving a particular meaning: pes = tempesta: 'storm, tempest'; te ='temps, time', lencia = clardat: 'brightness, light'; hence, heconcluded, the pestilencia was 'the time of tempest caused by light from the stars.'

And so, we have a better idea of what our German diarist meant when he said:

Due to war, pestilence, price rise and famine, our people arereduced to such an extent, that it will be difficult for ourdescendants to believe it.

On page 5 (101) of Mortimer's paper, we read that a young officer at the time of the sack of Magdeburg in 1631 wrote in his memoirs:

[A] grand storm-wind picked up, the town was inflamed at allpossible places, so that even little aid (rescue) was of help(appreciated). ... then I saw the whole town of Magdeburg, except dome,monastery and New Market, lying in embers and ashes, which raged onlyabout 3 or 3 1/2 hours, from which I deduced God's strange omnipotenceand punishment.

A "grand storm wind" and a town that was "inflamed" all over atonce, and burned to cinders in 3.5 hours? Perhaps the reader will liketo go back and re-read the description of how an overhead cometaryexplosion would manifest, quoted at the beginning of the previoussection, Wars, Pestilence and Witches.

Comets, like other marvels, were exploited by polemicists in prodigybooks. In 1661-1662, for example, radical English dissenters publishedsensationalist reports of prodigies, including comets, which gloomilygreeted the restoration of Charles II. ... There were no fewer thantwenty-five apparitions visible in seventeenth century Europe, andthese comets made frequent appearances in the polemical broadsheets andchapbooks hawked in the marketplaces...

Comets were apparently flinging all over the place during this time.One of these tracts shows comets in 1680, 1682, 1683. Another showsfive comets between 1664 and 1682. Another talks about comets of 1618.A tract entitled "The Signs of The Times" shows a bunch of prodigies that accompanied comets. Schechner writes:

All these outbursts were concerned with specific political quarrels.Some pamphleteers, however, raised themselves above the local roughwater to examine a larger vista. They thought they saw afast-approaching end to the world and their works adopted anapocalyptic tone. The comet of 1580 confirmed Francis Shakelton in hisopinion that the Day of Judgment was near at hand...

Although Regiomontanus and others agreed that 1588 would be a year of great revolutions and world mutations,Jesus had yet to reappear when William Lilly viewed the comets of 1664and 1665 and 1673 as tokens of the beginning of the end. In comets likethat of 1680, E. Tonge, Christopher Ness, and others saw the great"northern star" the messianic herald of the last days predicted by thesybyl Tiburtina and Tycho Brahe.

Panic and joy were heightened by the great conjunction of Jupiterand Saturn in the fiery trigon in 1682 which came on the heels of acomet's apparition. While great conjunctions take place every twentyyears, this one was part of an astrologically profound series ofconjunctions that commenced with the climacteric conjunction at theclose of the sixteenth century. By definition, climacteric conjunctionsoccurred only every eight hundred years when the great conjunction ofJupiter and Saturn returned to the sign of Aries and to the fierytrigon. It was widely reported by the popular press that Tycho Brahe,Johannes Kepler and Johann Heinrich Alsted correlated historicalperiods with climacteric conjunctions and believed that they portendedgreat mutations and reformations...

Tycho Brahe reckoned that all odd-numbered maximum conjunctionswere auspicious and urged people to look forward to the period of thesabbatical or seventh climacteric conjunction since the world'sCreation which he believed would follow the conjunction in Aries in1583. During the conjunctions in Leo in October 1682, the planetsallegedly would be in the same configuration as they had been at thebeginning of the world. Alsted believed this might be the lastconjunction of the present world and publicly announced that the Millennium would commence in 1694.

By itself, the great conjunction in the fiery trigon was a seriousmatter but its power was corroborated by several other signs. Marsjoined Jupiter and Saturn in 1682. There was a solar eclipse. But mostcritically, the great conjunction was ushered in by the comets of 1680and 1682 and the former was said to have been unrivaled in eighthundred years. Many thought the comets augured the Apocalypse... theend of the world...

In sensationalist street literature, radical pamphleteers took advantage of these comets... Atthe restoration, the Crown cracked down on the almanacs of Lilly andothers, blaming them for fomenting insurrection and irreligion duringthe Civil War and Interregnum...

The author next discusses the major controls put in place at thispoint to stamp out the popular discussion of predictions,interpretations... of "signs in the skies." So we can understand how somuch of this period of "panic" when "governments fell" was covered up.Based on the number of pamphlets and broadsides, it must have been areally crazy time and everybody was thinking the world was going toend. BUT, as we go through this description, we find a most interestingitem that relates to what our young officer witnessed at the fall ofMagdeburg:

The sunny disposition of the weather during the coronation (ofCharles II) was seen as the fulfillment of a prophecy. In 1630, at thetime of Charles' birth, a noonday star or rival sunallegedly had appeared in the sky. ... Aurelian Cook in TitusBritannicus explained its import: 'As soon as Born, Heaven took noticeof him, and eyed him with a star, appearing in defiance of the Sun at Noonday....'

For Cook, the extra sun announced that Charles ruled by divineright. Moreover, the timing of Charles' entry into London on hisbirthday was politically calculated to fulfill what had been portendedat his birth. Abraham Cowley, poet, diplomat and spy for the courtwrote:

No Star amongst ye all did, I beleeve,

Such Vigorous assistance give,

As that which thirty years ago,

At Charls his Birth, did in despight of the proud

Suns' Meridian Light,

His future Glories, this Year foreshow.

Edward Matthew devoted an entire book to the fulfillment of theprophecy declaring Charles "ordained to be the most Mighty Monarch inthe Universe..."

Charles' return was seen as a rebirth of England and duly recordedby a special act in the statute book, which proclaimed that 29 May wasthe most memorable Birth day not only of his Majesty both as a man andPrince, but likewise as an actual King...

So, a "second sun" was seen on and around May 29, 1630, and on May20, 1631, one year later, Magdeburg fell as described by our youngofficer.

The standard historical description of the Fall of Magdeburg goes pretty much as follows:

The fall of Magdeburg horrified Europe. The city had been starvedand then was bombarded unmercifully. The artillery shelling grew sobad, the town caught on fire. Over 20,000 of the citizens perished inthe siege and the cataclysm that ended it. The city itself was burnedto the ground. The cruel and pointless devastation marked a new low, anact abhorred by a generation well accustomed to horrors. [Link]

The war was to continue for 17 more years. 20 or 30 years later alot of new comets showed up, and I used to think that this "second sun"seen at the time of the birth of Charles II may have been an appearanceof our sun's twin in the far reaches of the solar system. However, withthe scientific information provided by Clube and Napier et al, I havechanged my view.

In any event, we begin to see why Clube wrote:

[W]hen the prospect of these global catastrophes recurs, such is thenerve-racking tension aroused in mankind that the principal leaders ofcivilization have long been in the habit of dissembling as to theircause (and likelihood) simply in order to preserve public calm andavoid the total breakdown of civil affairs. ...

The Christian, Islamic and Judaic cultures have all moved since theEuropean Renaissance to adopt an unreasoning anti-apocalyptic stance,apparently unaware of the burgeoning science of catastrophes. History,it now seems, is repeating itself: it has taken the Space Age to revivethe Platonist voice of reason but it emerges this time within a modernanti-fundamentalist, anti-apocalyptic tradition over which governmentsmay, as before, be unable to exercise control. The logical response isperhaps a commitment on the part of government to the voice of reasonand a decision to eliminate all signs as well as perpetrators of cosmiccatastrophes in order to appease a public not too far given to rabiduniformitarianism. Cynics ... would say that we do not needthe celestial threat to disguise Cold War intentions; rather we needthe Cold War to disguise celestial intentions!

We see that the events of those times have been covered up and/or forgotten, for the most part in their historical context.

Long after the event, John Dryden suggested that the comets of 1664and 1665 were related to the Sun that was seen at the birth of CharlesII. He described this apparition as "That bright companion of thesun..."

After the Thirty Years War was over, comets were associated withwitches and both were written off as superstition by the protestantswho pride themselves on having ushered in the scientific age. Andrew C.Fix, professor of History at LaFayette College, PA, writes:

Blathasar Bekker was a minister in the Dutch Reformed church firstin Friesland and then in Holland. He was educated in philosophy andtheology at the northern Dutch universities of Groningen and Franeker,becoming a Doctor of Theology at Franeker. Influenced by Cartesianphilosophy, he was an important critic of belief in witchcraft in hisbook De Betoverde Weerld (the World Bewitched) in which heargued against the possibility that disembodied spirits could contact,influence, or do evil to human beings, and thus against the possibilityof witchcraft. ...

After writing a work critical of the terrestrial influence of cometsBekker became interested in other popular superstitions includingwitchcraft and sorcery. He approached these topics from the point ofview of a Reformed minister upholding the power and earthly influenceof God against the supposed power of witches and spirits. ...

In the discussions around the Sabbath, the earthly effects ofcomets, and witchcraft Bekker was motivated in part by Cartesianrationalism, in part by his Calvinist idea of God's omnipotence, and inpart by his view of Scriptural exegesis, which included the doctrine ofaccommodation, the idea that God had in some places accommodated hisholy language to the limited understandings of men.

In volume one of The World Bewitched Bekker maintained thatbelief in the Devil and evil spirits as well as in such things asfortune telling, sorcery, and witchcraft were originally pagan beliefsfounded upon ignorance, prejudice, and fear that had over time creptinto the Catholic church and even into Bekker's own Reformed tradition.

Just after 6pm Friday 25th January, residents in the southern Frenchcity of Avignon rang the local police to report seeing "strange blueand green lights in the sky." Almost immediately Gendarmes andfirefighters took to the roads to follow the lights, fearing that theirsource may be an aircraft on fire and about to crash. However it wasquickly established that the blue and green trail of light was in factcoming from a meteorite.

The celestial body in question eventually fell to earth just after6.30pm, seven kilometres from Bourges in the centre of France. (BetweenBourges and the village of Trouy). Gendarmes were quickly on the scene,when local residents reported hearing a loud explosion.

Experts say, what fell to earth was only "a small chunk ofmeteorite". The small souvenir from space, landed in a field severalhundred metres from the nearest house. No one was injured and there wasno damage to buildings. The only trace that the chunk of meteorite evercame down was the small hole left on impact.

At the scene of the impact one local resident said that if the wholemeteorite had hit Bourges, the town might have been wiped off the faceof the Earth. Who said life in Bourges wasn't exciting!

Albuquerque, N.M. - An asteroid that exploded over Siberia a centuryago, leaving 800 square miles of scorched or blown down trees, wasn'tnearly as large as previously thought, a researcher concludes,suggesting a greater danger for Earth.

According to supercomputer simulations by Sandia NationalLaboratories physicist Mark Boslough, the asteroid that destroyed theforest at Tunguska in Siberia in June 1908 had a blast force equivalentto one-quarter to one-third of the 10- to 20-megaton range scientistspreviously estimated.

Better understanding of what happened at Tunguska will allow forbetter estimates of risk that would allow policymakers to decidewhether to try to deflect an asteroid or evacuate people in its path,he said.

"It's not clear whether a 10-megaton asteroid is more damaging thana Hurricane Katrina," Boslough said. "We can more accurately predictthe location of an impact and its time better than we can a hurricane,so you really could get people out of there if it's below a certainthreshold."

On Tuesday, an asteroid at least 800 feet long was making a rareclose pass by Earth, but scientists said there was no chance of animpact. The closest approach of 2007 TU24 will be 334,000 miles - about1.4 times the distance of Earth to the moon. An actual collision of asimilar-sized object with Earth occurs on average every 37,000 years.

Although the computer simulation shows the Tunguska asteroid wassmaller, its physical size isn't known. That would depend on suchfactors as speed, shape, how dense or porous it was and what it wasmade of, Boslough said.

Smaller asteroids approach Earth about three times more frequentlythan large ones. So if large asteroids approach about every 1,000years, a smaller one would be about every 300 years, Boslough said.

"Of course there's huge uncertainties," he said.

The three-dimensional computer simulations were done last summer.Boslough presented the findings at scientific meetings in September andDecember. A paper on the phenomenon, co-authored by Sandia researcherDave Crawford, has been accepted for publication in the International Journal of Impact Engineering.

The simulation, which better matches what's known of Tunguska thanearlier models did, shows that the center of the asteroid's massexploded above the ground, taking the form of a fireball blastingdownward faster than the speed of sound.

But the fireball did not reach the ground, so while miles of treesoutside the epicenter were flattened, those at the epicenter remainedstanding - scorched, with their branches stripped off.

Boslough said they were likened to telegraph poles by the firstRussian expedition to Tunguska - an expedition that didn't arrive until1927 because of the distance, primitive travel conditions and turbulenttimes in Russia.

If the asteroid had been as large as previously thought, "it wouldhave had really different effects on the ground," Boslough said.

"It wouldn't have just blown over trees. There would have been azone of completely scorched earth for several miles," he said. "Thatfireball would have come all the way down to the surface and everythingit came in contact with would have basically just vaporized."

Alan Harris, a planetary scientist at Space Science Institute inBoulder, Colo., said he's been following Boslough's work on Tunguskafor several years "and I think the idea that he has there seemed verysound."

"A meteorite or asteroid coming into Earth's atmosphere has a lot ofmomentum," he said. "The idea that it would push down into theatmosphere seems very plausible."

"The bottom line is it takes a lot less energy, a small explosion,to create ground damage" such as that at Tunguska, said Harris, whostudies the frequency of such impacts to assess hazards.

In the future, he said, he'll take Boslough's work into account and revise estimates of damage from impacts by smaller objects.

These low-resolution radar images of asteroid 2007 TU24 were taken over a few hours by the Goldstone Solar System Radar Telescope in California's Mojave Desert. Image resolution is approximately 20-meters per pixel. Next week, the plan is to have a combination of several telescopes provide higher resolution images.

"With these first radar observations finished, we can guarantee thatnext week's 1.4-lunar-distance approach is the closest until at leastthe end of the next century," said Steve Ostro, JPL astronomer andprincipal investigator for the project. "It is also the asteroid'sclosest Earth approach for more than 2,000 years."

Scientists at NASA's Near-Earth Object Program Office at JPL havedetermined that there is no possibility of an impact with Earth in theforeseeable future.

Asteroid 2007 TU24 was discovered by the NASA-sponsored Catalina SkySurvey on Oct. 11, 2007. The first radar detection of the asteroid wasacquired on Jan. 23 using the Goldstone 70-meter (230-foot) antenna.The Goldstone antenna is part of NASA's Deep Space Network Goldstonestation in Southern California's Mojave Desert. Goldstone's 70-meterdiameter (230-foot) antenna is capable of tracking a spacecrafttraveling more than 16 billion kilometers (10 billion miles) fromEarth. The surface of the 70-meter reflector must remain accuratewithin a fraction of the signal wavelength, meaning that the precisionacross the 3,850-square-meter (41,400-square-foot) surface ismaintained within one centimeter (0.4 inch).

Ostro and his team plan further radar observations of asteroid 2007TU24 using the National Science Foundation's Arecibo Observatory inPuerto Rico on Jan. 27-28 and Feb. 1-4.

The asteroid will reach an approximate apparent magnitude 10.3 onJan. 29-30 before quickly becoming fainter as it moves farther fromEarth. On that night, the asteroid will be observable in dark and clearskies through amateur telescopes with apertures of at least 7.6centimeters (three inches). An object with a magnitude of 10.3 is about50 times fainter than an object just visible to the naked eye in aclear, dark sky.

Scientists working with Ostro on the project include Lance Bennerand Jon Giorgini of JPL, Mike Nolan of the Arecibo Observatory, andGreg Black of the University of Virginia.

NASA detects and tracks asteroids and comets passing close to Earth.The Near Earth Object Observation Program, commonly called"Spaceguard," discovers, characterizes and computes trajectories forthese objects to determine if any could be potentially hazardous to ourplanet. The Arecibo Observatory is part of the National Astronomy andIonosphere Center, a national research center operated by CornellUniversity, Ithaca, N.Y., for the National Science Foundation.

The meteorite that stunned several Frenchpeople on January 25th , in the late afternoon, may not have fallen inthe surroundings of Bourges (Cher), as was first believed.

According to the research done by Dominique Caudron, an amateurastronomer in the North of France, the falling point would be located"a little bit toward the East of Albi, in the surroundings ofPaulinet".

In an article published by le Figaro, Pierre Lagrange, asociologist of sciences and member of the College of Experts working ina team of study and information on Unidentified Space Phenomena(Geipan) at the Centre National d'Etudes Spatiales (National Center ofSpace Studies) in Toulouse, gives a precise description of thecalculations of the young astronomer.

This new localization helps to understand the many reports fromwitnesses gathered in the Tarn department , even if the celestialobject was also seen in other departments of the 'Midi toulousain' (theregion surrounding Toulouse).

"Between 5:30 p.m. and 8 p.m. we saw very clearly a sort of 'skyrocket' falling in a diagonal direction in a forest at the end of theroute going from Vabre to Cunac".

"A fireball with a silvery tail. It was very low, I had the feelingthat it was going to hit my car...," remembers very clearly MicheleBoyer in Blaye-les-Mines.

"It was like a rocket with sparkles all around. It was only threemeters from the ground. In my opinion, it fell either on the hedge oron the neighbouring field," says Guy Morandin, a citizen of Albi.

Jacques Patenet, head of the Geipan at the CNES (National Center ofSpace Studies) in Toulouse confirmed yesterday evening the accuracy ofDominique Cuadron's calculation and the new hypothesis of an almostvertical path above the Tarn department.

"An atmospheric entrance between 35 and 50 miles high is seen from avery, very long distance, specially if it is a big and dense meteoriteof metallic consistency. But most of the time, nothing reaches theground."

Calling for witnesses

According to the scientist from Toulouse, "it would be an exceptional thing if we could find anything".

Jacques Patenet invites the witnesses of this event to report theirobservations in order to confront and add accuracy to DominiqueCaudron's calculations.

Contact: geipan@cnes.fr

Some reports from eyewitnesses:

In the region of Toulouse, a luminous phenomenon was pointed out inseveral departments, among which we find the Haute-Garonne andespecially the Tarn.

Marc Fabre saw "a big white trail" above Puech Auriol (Castres's commune), while he was playing football with his son.

Mrs Enery, living in Gaillac, saw the meteorite "passing at a very,very high speed from West to East." Still in the Tarn department, Mr.Roquelaure from Lombers claims having seen "at exactly 6:15 p.m., whilehe was going back home from the hairdresser in Montdragon, a redfireball with a sparkling tail like the candles on a birthday cake..."

"I saw the meteorite here, in Auch, on Friday evening. It was a bigfireball that flew very rapidly across the sky at the Northeast while Iwas at a traffic light coming back from work. It was not dark yet, butthe phenomenon was very intense," explains Dominique Amouroux, one ofour readers from the Gers department. She is not the only one to haveseen the fireball in the sky above Gers. Laurent Azanowsky, aninhabitant of Arblade-le-Haut said: "I saw a fireball coming from theNorthwest and going Southeast, totally in the opposite direction towhat the people in Bourges report."

A woman from Auscitaine also saw the celestial body when driving onFriday, between 6 p.m. and 6:30 p.m., in Ordan-Larroque: "We were atthe exit of Ordan, on the road that goes to the forest of Auch. There,there are a few houses, and a lady who was in her garden also saw it,"she explains.

"It was something very shiny with a white trail. We have the feelingthat it fell vertically, on a field... But if that had been the case,there would have been a fire, woudn't it?" she asks. "We would like toknow the why, the how," she says, hoping that the beautiful show didnot end somewhere in a catastrophe.

Translated by SOTT.net

Comment: Sounds like maybe there were two of these fireballs in France that day, not just one, given the differences in the reports.